diff --git a/integration/grpc-js/google/protobuf/struct.ts b/integration/grpc-js/google/protobuf/struct.ts
index 5760ebc59..849206f64 100644
--- a/integration/grpc-js/google/protobuf/struct.ts
+++ b/integration/grpc-js/google/protobuf/struct.ts
@@ -184,10 +184,11 @@ export const Struct = {
 
   wrap(object: { [key: string]: any } | undefined): Struct {
     const struct = createBaseStruct();
+
     if (object !== undefined) {
-      Object.keys(object).forEach((key) => {
+      for (const key of Object.keys(object)) {
         struct.fields[key] = object[key];
-      });
+      }
     }
     return struct;
   },
@@ -195,9 +196,9 @@ export const Struct = {
   unwrap(message: Struct): { [key: string]: any } {
     const object: { [key: string]: any } = {};
     if (message.fields) {
-      Object.keys(message.fields).forEach((key) => {
+      for (const key of Object.keys(message.fields)) {
         object[key] = message.fields[key];
-      });
+      }
     }
     return object;
   },
diff --git a/integration/nestjs-simple/google/protobuf/struct.ts b/integration/nestjs-simple/google/protobuf/struct.ts
index a3485c05d..de6125dfb 100644
--- a/integration/nestjs-simple/google/protobuf/struct.ts
+++ b/integration/nestjs-simple/google/protobuf/struct.ts
@@ -87,10 +87,11 @@ function createBaseStruct(): Struct {
 export const Struct = {
   wrap(object: { [key: string]: any } | undefined): Struct {
     const struct = createBaseStruct();
+
     if (object !== undefined) {
-      Object.keys(object).forEach((key) => {
+      for (const key of Object.keys(object)) {
         struct.fields[key] = Value.wrap(object[key]);
-      });
+      }
     }
     return struct;
   },
@@ -98,9 +99,9 @@ export const Struct = {
   unwrap(message: Struct): { [key: string]: any } {
     const object: { [key: string]: any } = {};
     if (message.fields) {
-      Object.keys(message.fields).forEach((key) => {
+      for (const key of Object.keys(message.fields)) {
         object[key] = Value.unwrap(message.fields[key]);
-      });
+      }
     }
     return object;
   },
diff --git a/integration/nice-grpc/google/protobuf/struct.ts b/integration/nice-grpc/google/protobuf/struct.ts
index c14e39613..d773b780c 100644
--- a/integration/nice-grpc/google/protobuf/struct.ts
+++ b/integration/nice-grpc/google/protobuf/struct.ts
@@ -184,10 +184,11 @@ export const Struct = {
 
   wrap(object: { [key: string]: any } | undefined): Struct {
     const struct = createBaseStruct();
+
     if (object !== undefined) {
-      Object.keys(object).forEach((key) => {
+      for (const key of Object.keys(object)) {
         struct.fields[key] = object[key];
-      });
+      }
     }
     return struct;
   },
@@ -195,9 +196,9 @@ export const Struct = {
   unwrap(message: Struct): { [key: string]: any } {
     const object: { [key: string]: any } = {};
     if (message.fields) {
-      Object.keys(message.fields).forEach((key) => {
+      for (const key of Object.keys(message.fields)) {
         object[key] = message.fields[key];
-      });
+      }
     }
     return object;
   },
diff --git a/integration/oneof-unions-snake/google/protobuf/struct.ts b/integration/oneof-unions-snake/google/protobuf/struct.ts
index 4208674b9..76745053b 100644
--- a/integration/oneof-unions-snake/google/protobuf/struct.ts
+++ b/integration/oneof-unions-snake/google/protobuf/struct.ts
@@ -170,10 +170,11 @@ export const Struct = {
 
   wrap(object: { [key: string]: any } | undefined): Struct {
     const struct = createBaseStruct();
+
     if (object !== undefined) {
-      Object.keys(object).forEach((key) => {
+      for (const key of Object.keys(object)) {
         struct.fields[key] = object[key];
-      });
+      }
     }
     return struct;
   },
@@ -181,9 +182,9 @@ export const Struct = {
   unwrap(message: Struct): { [key: string]: any } {
     const object: { [key: string]: any } = {};
     if (message.fields) {
-      Object.keys(message.fields).forEach((key) => {
+      for (const key of Object.keys(message.fields)) {
         object[key] = message.fields[key];
-      });
+      }
     }
     return object;
   },
diff --git a/integration/oneof-unions/google/protobuf/struct.ts b/integration/oneof-unions/google/protobuf/struct.ts
index e7ee042b7..a12c690df 100644
--- a/integration/oneof-unions/google/protobuf/struct.ts
+++ b/integration/oneof-unions/google/protobuf/struct.ts
@@ -170,10 +170,11 @@ export const Struct = {
 
   wrap(object: { [key: string]: any } | undefined): Struct {
     const struct = createBaseStruct();
+
     if (object !== undefined) {
-      Object.keys(object).forEach((key) => {
+      for (const key of Object.keys(object)) {
         struct.fields[key] = object[key];
-      });
+      }
     }
     return struct;
   },
@@ -181,9 +182,9 @@ export const Struct = {
   unwrap(message: Struct): { [key: string]: any } {
     const object: { [key: string]: any } = {};
     if (message.fields) {
-      Object.keys(message.fields).forEach((key) => {
+      for (const key of Object.keys(message.fields)) {
         object[key] = message.fields[key];
-      });
+      }
     }
     return object;
   },
diff --git a/integration/simple-esmodule-interop/empty.bin b/integration/simple-esmodule-interop/empty.bin
new file mode 100644
index 000000000..fda409fb6
Binary files /dev/null and b/integration/simple-esmodule-interop/empty.bin differ
diff --git a/integration/simple-snake/google/protobuf/struct.ts b/integration/simple-snake/google/protobuf/struct.ts
index 5dc64396f..0a84f9dc7 100644
--- a/integration/simple-snake/google/protobuf/struct.ts
+++ b/integration/simple-snake/google/protobuf/struct.ts
@@ -184,10 +184,11 @@ export const Struct = {
 
   wrap(object: { [key: string]: any } | undefined): Struct {
     const struct = createBaseStruct();
+
     if (object !== undefined) {
-      Object.keys(object).forEach((key) => {
+      for (const key of Object.keys(object)) {
         struct.fields[key] = object[key];
-      });
+      }
     }
     return struct;
   },
@@ -195,9 +196,9 @@ export const Struct = {
   unwrap(message: Struct): { [key: string]: any } {
     const object: { [key: string]: any } = {};
     if (message.fields) {
-      Object.keys(message.fields).forEach((key) => {
+      for (const key of Object.keys(message.fields)) {
         object[key] = message.fields[key];
-      });
+      }
     }
     return object;
   },
diff --git a/integration/simple-string-enums/google/protobuf/struct.ts b/integration/simple-string-enums/google/protobuf/struct.ts
index e866f6505..8f12e5f25 100644
--- a/integration/simple-string-enums/google/protobuf/struct.ts
+++ b/integration/simple-string-enums/google/protobuf/struct.ts
@@ -194,10 +194,11 @@ export const Struct = {
 
   wrap(object: { [key: string]: any } | undefined): Struct {
     const struct = createBaseStruct();
+
     if (object !== undefined) {
-      Object.keys(object).forEach((key) => {
+      for (const key of Object.keys(object)) {
         struct.fields[key] = object[key];
-      });
+      }
     }
     return struct;
   },
@@ -205,9 +206,9 @@ export const Struct = {
   unwrap(message: Struct): { [key: string]: any } {
     const object: { [key: string]: any } = {};
     if (message.fields) {
-      Object.keys(message.fields).forEach((key) => {
+      for (const key of Object.keys(message.fields)) {
         object[key] = message.fields[key];
-      });
+      }
     }
     return object;
   },
diff --git a/integration/static-only-type-registry/google/protobuf/struct.ts b/integration/static-only-type-registry/google/protobuf/struct.ts
index 6d44332d0..ca34a0f08 100644
--- a/integration/static-only-type-registry/google/protobuf/struct.ts
+++ b/integration/static-only-type-registry/google/protobuf/struct.ts
@@ -187,10 +187,11 @@ export const Struct = {
 
   wrap(object: { [key: string]: any } | undefined): Struct {
     const struct = createBaseStruct();
+
     if (object !== undefined) {
-      Object.keys(object).forEach((key) => {
+      for (const key of Object.keys(object)) {
         struct.fields[key] = object[key];
-      });
+      }
     }
     return struct;
   },
@@ -198,9 +199,9 @@ export const Struct = {
   unwrap(message: Struct): { [key: string]: any } {
     const object: { [key: string]: any } = {};
     if (message.fields) {
-      Object.keys(message.fields).forEach((key) => {
+      for (const key of Object.keys(message.fields)) {
         object[key] = message.fields[key];
-      });
+      }
     }
     return object;
   },
diff --git a/integration/static-only/google/protobuf/struct.ts b/integration/static-only/google/protobuf/struct.ts
index 4831a6f92..046a09e01 100644
--- a/integration/static-only/google/protobuf/struct.ts
+++ b/integration/static-only/google/protobuf/struct.ts
@@ -186,10 +186,11 @@ export const Struct = {
 
   wrap(object: { [key: string]: any } | undefined): Struct {
     const struct = createBaseStruct();
+
     if (object !== undefined) {
-      Object.keys(object).forEach((key) => {
+      for (const key of Object.keys(object)) {
         struct.fields[key] = object[key];
-      });
+      }
     }
     return struct;
   },
@@ -197,9 +198,9 @@ export const Struct = {
   unwrap(message: Struct): { [key: string]: any } {
     const object: { [key: string]: any } = {};
     if (message.fields) {
-      Object.keys(message.fields).forEach((key) => {
+      for (const key of Object.keys(message.fields)) {
         object[key] = message.fields[key];
-      });
+      }
     }
     return object;
   },
diff --git a/integration/struct/google/protobuf/struct.ts b/integration/struct/google/protobuf/struct.ts
index 5760ebc59..849206f64 100644
--- a/integration/struct/google/protobuf/struct.ts
+++ b/integration/struct/google/protobuf/struct.ts
@@ -184,10 +184,11 @@ export const Struct = {
 
   wrap(object: { [key: string]: any } | undefined): Struct {
     const struct = createBaseStruct();
+
     if (object !== undefined) {
-      Object.keys(object).forEach((key) => {
+      for (const key of Object.keys(object)) {
         struct.fields[key] = object[key];
-      });
+      }
     }
     return struct;
   },
@@ -195,9 +196,9 @@ export const Struct = {
   unwrap(message: Struct): { [key: string]: any } {
     const object: { [key: string]: any } = {};
     if (message.fields) {
-      Object.keys(message.fields).forEach((key) => {
+      for (const key of Object.keys(message.fields)) {
         object[key] = message.fields[key];
-      });
+      }
     }
     return object;
   },
diff --git a/integration/type-annotations/google/protobuf/struct.ts b/integration/type-annotations/google/protobuf/struct.ts
index e1cd21542..de5edcd11 100644
--- a/integration/type-annotations/google/protobuf/struct.ts
+++ b/integration/type-annotations/google/protobuf/struct.ts
@@ -194,10 +194,11 @@ export const Struct = {
 
   wrap(object: { [key: string]: any } | undefined): Struct {
     const struct = createBaseStruct();
+
     if (object !== undefined) {
-      Object.keys(object).forEach((key) => {
+      for (const key of Object.keys(object)) {
         struct.fields[key] = object[key];
-      });
+      }
     }
     return struct;
   },
@@ -205,9 +206,9 @@ export const Struct = {
   unwrap(message: Struct): { [key: string]: any } {
     const object: { [key: string]: any } = {};
     if (message.fields) {
-      Object.keys(message.fields).forEach((key) => {
+      for (const key of Object.keys(message.fields)) {
         object[key] = message.fields[key];
-      });
+      }
     }
     return object;
   },
diff --git a/integration/type-registry/google/protobuf/struct.ts b/integration/type-registry/google/protobuf/struct.ts
index 122718b12..3f445b3de 100644
--- a/integration/type-registry/google/protobuf/struct.ts
+++ b/integration/type-registry/google/protobuf/struct.ts
@@ -195,10 +195,11 @@ export const Struct = {
 
   wrap(object: { [key: string]: any } | undefined): Struct {
     const struct = createBaseStruct();
+
     if (object !== undefined) {
-      Object.keys(object).forEach((key) => {
+      for (const key of Object.keys(object)) {
         struct.fields[key] = object[key];
-      });
+      }
     }
     return struct;
   },
@@ -206,9 +207,9 @@ export const Struct = {
   unwrap(message: Struct): { [key: string]: any } {
     const object: { [key: string]: any } = {};
     if (message.fields) {
-      Object.keys(message.fields).forEach((key) => {
+      for (const key of Object.keys(message.fields)) {
         object[key] = message.fields[key];
-      });
+      }
     }
     return object;
   },
diff --git a/integration/use-map-type/google/protobuf/struct.ts b/integration/use-map-type/google/protobuf/struct.ts
index ca709b109..1d5514fa1 100644
--- a/integration/use-map-type/google/protobuf/struct.ts
+++ b/integration/use-map-type/google/protobuf/struct.ts
@@ -181,19 +181,22 @@ export const Struct = {
 
   wrap(object: { [key: string]: any } | undefined): Struct {
     const struct = createBaseStruct();
+
     if (object !== undefined) {
-      Object.keys(object).forEach((key) => {
+      for (const key of Object.keys(object)) {
         struct.fields.set(key, object[key]);
-      });
+      }
     }
     return struct;
   },
 
   unwrap(message: Struct): { [key: string]: any } {
     const object: { [key: string]: any } = {};
-    [...message.fields.keys()].forEach((key) => {
-      object[key] = message.fields.get(key);
-    });
+    if (message.fields) {
+      for (const key of message.fields.keys()) {
+        object[key] = message.fields.get(key);
+      }
+    }
     return object;
   },
 };
diff --git a/integration/use-numeric-enum-json/google/protobuf/struct.ts b/integration/use-numeric-enum-json/google/protobuf/struct.ts
index 276b617e8..956cb310e 100644
--- a/integration/use-numeric-enum-json/google/protobuf/struct.ts
+++ b/integration/use-numeric-enum-json/google/protobuf/struct.ts
@@ -184,10 +184,11 @@ export const Struct = {
 
   wrap(object: { [key: string]: any } | undefined): Struct {
     const struct = createBaseStruct();
+
     if (object !== undefined) {
-      Object.keys(object).forEach((key) => {
+      for (const key of Object.keys(object)) {
         struct.fields[key] = object[key];
-      });
+      }
     }
     return struct;
   },
@@ -195,9 +196,9 @@ export const Struct = {
   unwrap(message: Struct): { [key: string]: any } {
     const object: { [key: string]: any } = {};
     if (message.fields) {
-      Object.keys(message.fields).forEach((key) => {
+      for (const key of Object.keys(message.fields)) {
         object[key] = message.fields[key];
-      });
+      }
     }
     return object;
   },
diff --git a/integration/use-optionals-all/google/protobuf/struct.ts b/integration/use-optionals-all/google/protobuf/struct.ts
new file mode 100644
index 000000000..e465e0978
--- /dev/null
+++ b/integration/use-optionals-all/google/protobuf/struct.ts
@@ -0,0 +1,550 @@
+/* eslint-disable */
+import * as _m0 from "protobufjs/minimal";
+
+export const protobufPackage = "google.protobuf";
+
+/**
+ * `NullValue` is a singleton enumeration to represent the null value for the
+ * `Value` type union.
+ *
+ *  The JSON representation for `NullValue` is JSON `null`.
+ */
+export enum NullValue {
+  /** NULL_VALUE - Null value. */
+  NULL_VALUE = 0,
+  UNRECOGNIZED = -1,
+}
+
+export function nullValueFromJSON(object: any): NullValue {
+  switch (object) {
+    case 0:
+    case "NULL_VALUE":
+      return NullValue.NULL_VALUE;
+    case -1:
+    case "UNRECOGNIZED":
+    default:
+      return NullValue.UNRECOGNIZED;
+  }
+}
+
+export function nullValueToJSON(object: NullValue): string {
+  switch (object) {
+    case NullValue.NULL_VALUE:
+      return "NULL_VALUE";
+    case NullValue.UNRECOGNIZED:
+    default:
+      return "UNRECOGNIZED";
+  }
+}
+
+/**
+ * `Struct` represents a structured data value, consisting of fields
+ * which map to dynamically typed values. In some languages, `Struct`
+ * might be supported by a native representation. For example, in
+ * scripting languages like JS a struct is represented as an
+ * object. The details of that representation are described together
+ * with the proto support for the language.
+ *
+ * The JSON representation for `Struct` is JSON object.
+ */
+export interface Struct {
+  /** Unordered map of dynamically typed values. */
+  fields?: { [key: string]: any | undefined } | undefined;
+}
+
+export interface Struct_FieldsEntry {
+  key: string;
+  value?: any | undefined;
+}
+
+/**
+ * `Value` represents a dynamically typed value which can be either
+ * null, a number, a string, a boolean, a recursive struct value, or a
+ * list of values. A producer of value is expected to set one of these
+ * variants. Absence of any variant indicates an error.
+ *
+ * The JSON representation for `Value` is JSON value.
+ */
+export interface Value {
+  /** Represents a null value. */
+  nullValue?:
+    | NullValue
+    | undefined;
+  /** Represents a double value. */
+  numberValue?:
+    | number
+    | undefined;
+  /** Represents a string value. */
+  stringValue?:
+    | string
+    | undefined;
+  /** Represents a boolean value. */
+  boolValue?:
+    | boolean
+    | undefined;
+  /** Represents a structured value. */
+  structValue?:
+    | { [key: string]: any }
+    | undefined;
+  /** Represents a repeated `Value`. */
+  listValue?: Array<any> | undefined;
+}
+
+/**
+ * `ListValue` is a wrapper around a repeated field of values.
+ *
+ * The JSON representation for `ListValue` is JSON array.
+ */
+export interface ListValue {
+  /** Repeated field of dynamically typed values. */
+  values?: any[] | undefined;
+}
+
+function createBaseStruct(): Struct {
+  return { fields: {} };
+}
+
+export const Struct = {
+  encode(message: Struct, writer: _m0.Writer = _m0.Writer.create()): _m0.Writer {
+    Object.entries(message.fields || {}).forEach(([key, value]) => {
+      if (value !== undefined) {
+        Struct_FieldsEntry.encode({ key: key as any, value }, writer.uint32(10).fork()).ldelim();
+      }
+    });
+    return writer;
+  },
+
+  decode(input: _m0.Reader | Uint8Array, length?: number): Struct {
+    const reader = input instanceof _m0.Reader ? input : _m0.Reader.create(input);
+    let end = length === undefined ? reader.len : reader.pos + length;
+    const message = createBaseStruct();
+    while (reader.pos < end) {
+      const tag = reader.uint32();
+      switch (tag >>> 3) {
+        case 1:
+          if (tag !== 10) {
+            break;
+          }
+
+          const entry1 = Struct_FieldsEntry.decode(reader, reader.uint32());
+          if (entry1.value !== undefined) {
+            message.fields![entry1.key] = entry1.value;
+          }
+          continue;
+      }
+      if ((tag & 7) === 4 || tag === 0) {
+        break;
+      }
+      reader.skipType(tag & 7);
+    }
+    return message;
+  },
+
+  fromJSON(object: any): Struct {
+    return {
+      fields: isObject(object.fields)
+        ? Object.entries(object.fields).reduce<{ [key: string]: any | undefined }>((acc, [key, value]) => {
+          acc[key] = value as any | undefined;
+          return acc;
+        }, {})
+        : {},
+    };
+  },
+
+  toJSON(message: Struct): unknown {
+    const obj: any = {};
+    if (message.fields) {
+      const entries = Object.entries(message.fields);
+      if (entries.length > 0) {
+        obj.fields = {};
+        entries.forEach(([k, v]) => {
+          obj.fields[k] = v;
+        });
+      }
+    }
+    return obj;
+  },
+
+  create<I extends Exact<DeepPartial<Struct>, I>>(base?: I): Struct {
+    return Struct.fromPartial(base ?? ({} as any));
+  },
+  fromPartial<I extends Exact<DeepPartial<Struct>, I>>(object: I): Struct {
+    const message = createBaseStruct();
+    message.fields = Object.entries(object.fields ?? {}).reduce<{ [key: string]: any | undefined }>(
+      (acc, [key, value]) => {
+        if (value !== undefined) {
+          acc[key] = value;
+        }
+        return acc;
+      },
+      {},
+    );
+    return message;
+  },
+
+  wrap(object: { [key: string]: any } | undefined): Struct {
+    const struct = createBaseStruct();
+    struct.fields ??= {};
+    if (object !== undefined) {
+      for (const key of Object.keys(object)) {
+        struct.fields[key] = object[key];
+      }
+    }
+    return struct;
+  },
+
+  unwrap(message: Struct): { [key: string]: any } {
+    const object: { [key: string]: any } = {};
+    if (message.fields) {
+      for (const key of Object.keys(message.fields)) {
+        object[key] = message.fields[key];
+      }
+    }
+    return object;
+  },
+};
+
+function createBaseStruct_FieldsEntry(): Struct_FieldsEntry {
+  return { key: "", value: undefined };
+}
+
+export const Struct_FieldsEntry = {
+  encode(message: Struct_FieldsEntry, writer: _m0.Writer = _m0.Writer.create()): _m0.Writer {
+    if (message.key !== "") {
+      writer.uint32(10).string(message.key);
+    }
+    if (message.value !== undefined) {
+      Value.encode(Value.wrap(message.value), writer.uint32(18).fork()).ldelim();
+    }
+    return writer;
+  },
+
+  decode(input: _m0.Reader | Uint8Array, length?: number): Struct_FieldsEntry {
+    const reader = input instanceof _m0.Reader ? input : _m0.Reader.create(input);
+    let end = length === undefined ? reader.len : reader.pos + length;
+    const message = createBaseStruct_FieldsEntry();
+    while (reader.pos < end) {
+      const tag = reader.uint32();
+      switch (tag >>> 3) {
+        case 1:
+          if (tag !== 10) {
+            break;
+          }
+
+          message.key = reader.string();
+          continue;
+        case 2:
+          if (tag !== 18) {
+            break;
+          }
+
+          message.value = Value.unwrap(Value.decode(reader, reader.uint32()));
+          continue;
+      }
+      if ((tag & 7) === 4 || tag === 0) {
+        break;
+      }
+      reader.skipType(tag & 7);
+    }
+    return message;
+  },
+
+  fromJSON(object: any): Struct_FieldsEntry {
+    return {
+      key: isSet(object.key) ? globalThis.String(object.key) : "",
+      value: isSet(object?.value) ? object.value : undefined,
+    };
+  },
+
+  toJSON(message: Struct_FieldsEntry): unknown {
+    const obj: any = {};
+    if (message.key !== "") {
+      obj.key = message.key;
+    }
+    if (message.value !== undefined) {
+      obj.value = message.value;
+    }
+    return obj;
+  },
+
+  create<I extends Exact<DeepPartial<Struct_FieldsEntry>, I>>(base?: I): Struct_FieldsEntry {
+    return Struct_FieldsEntry.fromPartial(base ?? ({} as any));
+  },
+  fromPartial<I extends Exact<DeepPartial<Struct_FieldsEntry>, I>>(object: I): Struct_FieldsEntry {
+    const message = createBaseStruct_FieldsEntry();
+    message.key = object.key ?? "";
+    message.value = object.value ?? undefined;
+    return message;
+  },
+};
+
+function createBaseValue(): Value {
+  return {
+    nullValue: undefined,
+    numberValue: undefined,
+    stringValue: undefined,
+    boolValue: undefined,
+    structValue: undefined,
+    listValue: undefined,
+  };
+}
+
+export const Value = {
+  encode(message: Value, writer: _m0.Writer = _m0.Writer.create()): _m0.Writer {
+    if (message.nullValue !== undefined) {
+      writer.uint32(8).int32(message.nullValue);
+    }
+    if (message.numberValue !== undefined) {
+      writer.uint32(17).double(message.numberValue);
+    }
+    if (message.stringValue !== undefined) {
+      writer.uint32(26).string(message.stringValue);
+    }
+    if (message.boolValue !== undefined) {
+      writer.uint32(32).bool(message.boolValue);
+    }
+    if (message.structValue !== undefined) {
+      Struct.encode(Struct.wrap(message.structValue), writer.uint32(42).fork()).ldelim();
+    }
+    if (message.listValue !== undefined) {
+      ListValue.encode(ListValue.wrap(message.listValue), writer.uint32(50).fork()).ldelim();
+    }
+    return writer;
+  },
+
+  decode(input: _m0.Reader | Uint8Array, length?: number): Value {
+    const reader = input instanceof _m0.Reader ? input : _m0.Reader.create(input);
+    let end = length === undefined ? reader.len : reader.pos + length;
+    const message = createBaseValue();
+    while (reader.pos < end) {
+      const tag = reader.uint32();
+      switch (tag >>> 3) {
+        case 1:
+          if (tag !== 8) {
+            break;
+          }
+
+          message.nullValue = reader.int32() as any;
+          continue;
+        case 2:
+          if (tag !== 17) {
+            break;
+          }
+
+          message.numberValue = reader.double();
+          continue;
+        case 3:
+          if (tag !== 26) {
+            break;
+          }
+
+          message.stringValue = reader.string();
+          continue;
+        case 4:
+          if (tag !== 32) {
+            break;
+          }
+
+          message.boolValue = reader.bool();
+          continue;
+        case 5:
+          if (tag !== 42) {
+            break;
+          }
+
+          message.structValue = Struct.unwrap(Struct.decode(reader, reader.uint32()));
+          continue;
+        case 6:
+          if (tag !== 50) {
+            break;
+          }
+
+          message.listValue = ListValue.unwrap(ListValue.decode(reader, reader.uint32()));
+          continue;
+      }
+      if ((tag & 7) === 4 || tag === 0) {
+        break;
+      }
+      reader.skipType(tag & 7);
+    }
+    return message;
+  },
+
+  fromJSON(object: any): Value {
+    return {
+      nullValue: isSet(object.nullValue) ? nullValueFromJSON(object.nullValue) : undefined,
+      numberValue: isSet(object.numberValue) ? globalThis.Number(object.numberValue) : undefined,
+      stringValue: isSet(object.stringValue) ? globalThis.String(object.stringValue) : undefined,
+      boolValue: isSet(object.boolValue) ? globalThis.Boolean(object.boolValue) : undefined,
+      structValue: isObject(object.structValue) ? object.structValue : undefined,
+      listValue: globalThis.Array.isArray(object.listValue) ? [...object.listValue] : undefined,
+    };
+  },
+
+  toJSON(message: Value): unknown {
+    const obj: any = {};
+    if (message.nullValue !== undefined) {
+      obj.nullValue = nullValueToJSON(message.nullValue);
+    }
+    if (message.numberValue !== undefined) {
+      obj.numberValue = message.numberValue;
+    }
+    if (message.stringValue !== undefined) {
+      obj.stringValue = message.stringValue;
+    }
+    if (message.boolValue !== undefined) {
+      obj.boolValue = message.boolValue;
+    }
+    if (message.structValue !== undefined) {
+      obj.structValue = message.structValue;
+    }
+    if (message.listValue !== undefined) {
+      obj.listValue = message.listValue;
+    }
+    return obj;
+  },
+
+  create<I extends Exact<DeepPartial<Value>, I>>(base?: I): Value {
+    return Value.fromPartial(base ?? ({} as any));
+  },
+  fromPartial<I extends Exact<DeepPartial<Value>, I>>(object: I): Value {
+    const message = createBaseValue();
+    message.nullValue = object.nullValue ?? undefined;
+    message.numberValue = object.numberValue ?? undefined;
+    message.stringValue = object.stringValue ?? undefined;
+    message.boolValue = object.boolValue ?? undefined;
+    message.structValue = object.structValue ?? undefined;
+    message.listValue = object.listValue ?? undefined;
+    return message;
+  },
+
+  wrap(value: any): Value {
+    const result = createBaseValue();
+    if (value === null) {
+      result.nullValue = NullValue.NULL_VALUE;
+    } else if (typeof value === "boolean") {
+      result.boolValue = value;
+    } else if (typeof value === "number") {
+      result.numberValue = value;
+    } else if (typeof value === "string") {
+      result.stringValue = value;
+    } else if (globalThis.Array.isArray(value)) {
+      result.listValue = value;
+    } else if (typeof value === "object") {
+      result.structValue = value;
+    } else if (typeof value !== "undefined") {
+      throw new globalThis.Error("Unsupported any value type: " + typeof value);
+    }
+    return result;
+  },
+
+  unwrap(message: any): string | number | boolean | Object | null | Array<any> | undefined {
+    if (message.stringValue !== undefined) {
+      return message.stringValue;
+    } else if (message?.numberValue !== undefined) {
+      return message.numberValue;
+    } else if (message?.boolValue !== undefined) {
+      return message.boolValue;
+    } else if (message?.structValue !== undefined) {
+      return message.structValue as any;
+    } else if (message?.listValue !== undefined) {
+      return message.listValue;
+    } else if (message?.nullValue !== undefined) {
+      return null;
+    }
+    return undefined;
+  },
+};
+
+function createBaseListValue(): ListValue {
+  return { values: [] };
+}
+
+export const ListValue = {
+  encode(message: ListValue, writer: _m0.Writer = _m0.Writer.create()): _m0.Writer {
+    if (message.values !== undefined && message.values.length !== 0) {
+      for (const v of message.values) {
+        Value.encode(Value.wrap(v!), writer.uint32(10).fork()).ldelim();
+      }
+    }
+    return writer;
+  },
+
+  decode(input: _m0.Reader | Uint8Array, length?: number): ListValue {
+    const reader = input instanceof _m0.Reader ? input : _m0.Reader.create(input);
+    let end = length === undefined ? reader.len : reader.pos + length;
+    const message = createBaseListValue();
+    while (reader.pos < end) {
+      const tag = reader.uint32();
+      switch (tag >>> 3) {
+        case 1:
+          if (tag !== 10) {
+            break;
+          }
+
+          message.values!.push(Value.unwrap(Value.decode(reader, reader.uint32())));
+          continue;
+      }
+      if ((tag & 7) === 4 || tag === 0) {
+        break;
+      }
+      reader.skipType(tag & 7);
+    }
+    return message;
+  },
+
+  fromJSON(object: any): ListValue {
+    return { values: globalThis.Array.isArray(object?.values) ? [...object.values] : [] };
+  },
+
+  toJSON(message: ListValue): unknown {
+    const obj: any = {};
+    if (message.values?.length) {
+      obj.values = message.values;
+    }
+    return obj;
+  },
+
+  create<I extends Exact<DeepPartial<ListValue>, I>>(base?: I): ListValue {
+    return ListValue.fromPartial(base ?? ({} as any));
+  },
+  fromPartial<I extends Exact<DeepPartial<ListValue>, I>>(object: I): ListValue {
+    const message = createBaseListValue();
+    message.values = object.values?.map((e) => e) || [];
+    return message;
+  },
+
+  wrap(array: Array<any> | undefined): ListValue {
+    const result = createBaseListValue();
+    result.values = array ?? [];
+    return result;
+  },
+
+  unwrap(message: ListValue): Array<any> {
+    if (message?.hasOwnProperty("values") && globalThis.Array.isArray(message.values)) {
+      return message.values;
+    } else {
+      return message as any;
+    }
+  },
+};
+
+type Builtin = Date | Function | Uint8Array | string | number | boolean | undefined;
+
+export type DeepPartial<T> = T extends Builtin ? T
+  : T extends globalThis.Array<infer U> ? globalThis.Array<DeepPartial<U>>
+  : T extends ReadonlyArray<infer U> ? ReadonlyArray<DeepPartial<U>>
+  : T extends {} ? { [K in keyof T]?: DeepPartial<T[K]> }
+  : Partial<T>;
+
+type KeysOfUnion<T> = T extends T ? keyof T : never;
+export type Exact<P, I extends P> = P extends Builtin ? P
+  : P & { [K in keyof P]: Exact<P[K], I[K]> } & { [K in Exclude<keyof I, KeysOfUnion<P>>]: never };
+
+function isObject(value: any): boolean {
+  return typeof value === "object" && value !== null;
+}
+
+function isSet(value: any): boolean {
+  return value !== null && value !== undefined;
+}
diff --git a/integration/use-optionals-all/test.bin b/integration/use-optionals-all/test.bin
index 9cf270203..18b318f74 100644
Binary files a/integration/use-optionals-all/test.bin and b/integration/use-optionals-all/test.bin differ
diff --git a/integration/use-optionals-all/test.proto b/integration/use-optionals-all/test.proto
index 754ebf3b6..71de752d6 100644
--- a/integration/use-optionals-all/test.proto
+++ b/integration/use-optionals-all/test.proto
@@ -2,6 +2,7 @@ syntax = "proto3";
 package optionalstest;
 
 import "google/protobuf/timestamp.proto";
+import "google/protobuf/struct.proto";
 
 message OptionalsTest {
   int32 id = 1;
@@ -31,6 +32,7 @@ message OptionalsTest {
   map<string, string> translations = 30;
 
   google.protobuf.Timestamp timestamp = 31;
+  google.protobuf.Struct struct = 32;
 }
 
 enum StateEnum {
diff --git a/integration/use-optionals-all/test.ts b/integration/use-optionals-all/test.ts
index bb2115609..5ddbea317 100644
--- a/integration/use-optionals-all/test.ts
+++ b/integration/use-optionals-all/test.ts
@@ -1,5 +1,6 @@
 /* eslint-disable */
 import * as _m0 from "protobufjs/minimal";
+import { Struct } from "./google/protobuf/struct";
 import { Timestamp } from "./google/protobuf/timestamp";
 import Long = require("long");
 
@@ -68,6 +69,7 @@ export interface OptionalsTest {
   optData?: Uint8Array | undefined;
   translations?: { [key: string]: string } | undefined;
   timestamp?: Date | undefined;
+  struct?: { [key: string]: any } | undefined;
 }
 
 export interface OptionalsTest_TranslationsEntry {
@@ -103,6 +105,7 @@ function createBaseOptionalsTest(): OptionalsTest {
     optData: undefined,
     translations: {},
     timestamp: undefined,
+    struct: undefined,
   };
 }
 
@@ -199,6 +202,9 @@ export const OptionalsTest = {
     if (message.timestamp !== undefined) {
       Timestamp.encode(toTimestamp(message.timestamp), writer.uint32(250).fork()).ldelim();
     }
+    if (message.struct !== undefined) {
+      Struct.encode(Struct.wrap(message.struct), writer.uint32(258).fork()).ldelim();
+    }
     return writer;
   },
 
@@ -413,6 +419,13 @@ export const OptionalsTest = {
 
           message.timestamp = fromTimestamp(Timestamp.decode(reader, reader.uint32()));
           continue;
+        case 32:
+          if (tag !== 258) {
+            break;
+          }
+
+          message.struct = Struct.unwrap(Struct.decode(reader, reader.uint32()));
+          continue;
       }
       if ((tag & 7) === 4 || tag === 0) {
         break;
@@ -456,6 +469,7 @@ export const OptionalsTest = {
         }, {})
         : {},
       timestamp: isSet(object.timestamp) ? fromJsonTimestamp(object.timestamp) : undefined,
+      struct: isObject(object.struct) ? object.struct : undefined,
     };
   },
 
@@ -536,6 +550,9 @@ export const OptionalsTest = {
     if (message.timestamp !== undefined) {
       obj.timestamp = message.timestamp.toISOString();
     }
+    if (message.struct !== undefined) {
+      obj.struct = message.struct;
+    }
     return obj;
   },
 
@@ -577,6 +594,7 @@ export const OptionalsTest = {
       {},
     );
     message.timestamp = object.timestamp ?? undefined;
+    message.struct = object.struct ?? undefined;
     return message;
   },
 };
diff --git a/integration/use-optionals-no-undefined/google/protobuf/struct.ts b/integration/use-optionals-no-undefined/google/protobuf/struct.ts
new file mode 100644
index 000000000..6b72c2577
--- /dev/null
+++ b/integration/use-optionals-no-undefined/google/protobuf/struct.ts
@@ -0,0 +1,548 @@
+/* eslint-disable */
+import * as _m0 from "protobufjs/minimal";
+
+export const protobufPackage = "google.protobuf";
+
+/**
+ * `NullValue` is a singleton enumeration to represent the null value for the
+ * `Value` type union.
+ *
+ *  The JSON representation for `NullValue` is JSON `null`.
+ */
+export enum NullValue {
+  /** NULL_VALUE - Null value. */
+  NULL_VALUE = 0,
+  UNRECOGNIZED = -1,
+}
+
+export function nullValueFromJSON(object: any): NullValue {
+  switch (object) {
+    case 0:
+    case "NULL_VALUE":
+      return NullValue.NULL_VALUE;
+    case -1:
+    case "UNRECOGNIZED":
+    default:
+      return NullValue.UNRECOGNIZED;
+  }
+}
+
+export function nullValueToJSON(object: NullValue): string {
+  switch (object) {
+    case NullValue.NULL_VALUE:
+      return "NULL_VALUE";
+    case NullValue.UNRECOGNIZED:
+    default:
+      return "UNRECOGNIZED";
+  }
+}
+
+/**
+ * `Struct` represents a structured data value, consisting of fields
+ * which map to dynamically typed values. In some languages, `Struct`
+ * might be supported by a native representation. For example, in
+ * scripting languages like JS a struct is represented as an
+ * object. The details of that representation are described together
+ * with the proto support for the language.
+ *
+ * The JSON representation for `Struct` is JSON object.
+ */
+export interface Struct {
+  /** Unordered map of dynamically typed values. */
+  fields?: { [key: string]: any | undefined } | undefined;
+}
+
+export interface Struct_FieldsEntry {
+  key: string;
+  value?: any | undefined;
+}
+
+/**
+ * `Value` represents a dynamically typed value which can be either
+ * null, a number, a string, a boolean, a recursive struct value, or a
+ * list of values. A producer of value is expected to set one of these
+ * variants. Absence of any variant indicates an error.
+ *
+ * The JSON representation for `Value` is JSON value.
+ */
+export interface Value {
+  /** Represents a null value. */
+  nullValue?:
+    | NullValue
+    | undefined;
+  /** Represents a double value. */
+  numberValue?:
+    | number
+    | undefined;
+  /** Represents a string value. */
+  stringValue?:
+    | string
+    | undefined;
+  /** Represents a boolean value. */
+  boolValue?:
+    | boolean
+    | undefined;
+  /** Represents a structured value. */
+  structValue?:
+    | { [key: string]: any }
+    | undefined;
+  /** Represents a repeated `Value`. */
+  listValue?: Array<any> | undefined;
+}
+
+/**
+ * `ListValue` is a wrapper around a repeated field of values.
+ *
+ * The JSON representation for `ListValue` is JSON array.
+ */
+export interface ListValue {
+  /** Repeated field of dynamically typed values. */
+  values?: any[] | undefined;
+}
+
+function createBaseStruct(): Struct {
+  return {};
+}
+
+export const Struct = {
+  encode(message: Struct, writer: _m0.Writer = _m0.Writer.create()): _m0.Writer {
+    Object.entries(message.fields || {}).forEach(([key, value]) => {
+      if (value !== undefined) {
+        Struct_FieldsEntry.encode({ key: key as any, value }, writer.uint32(10).fork()).ldelim();
+      }
+    });
+    return writer;
+  },
+
+  decode(input: _m0.Reader | Uint8Array, length?: number): Struct {
+    const reader = input instanceof _m0.Reader ? input : _m0.Reader.create(input);
+    let end = length === undefined ? reader.len : reader.pos + length;
+    const message = createBaseStruct();
+    while (reader.pos < end) {
+      const tag = reader.uint32();
+      switch (tag >>> 3) {
+        case 1:
+          if (tag !== 10) {
+            break;
+          }
+
+          const entry1 = Struct_FieldsEntry.decode(reader, reader.uint32());
+          if (entry1.value !== undefined) {
+            if (message.fields === undefined) {
+              message.fields = {};
+            }
+            message.fields![entry1.key] = entry1.value;
+          }
+          continue;
+      }
+      if ((tag & 7) === 4 || tag === 0) {
+        break;
+      }
+      reader.skipType(tag & 7);
+    }
+    return message;
+  },
+
+  fromJSON(object: any): Struct {
+    return {
+      fields: isObject(object.fields)
+        ? Object.entries(object.fields).reduce<{ [key: string]: any | undefined }>((acc, [key, value]) => {
+          acc[key] = value as any | undefined;
+          return acc;
+        }, {})
+        : undefined,
+    };
+  },
+
+  toJSON(message: Struct): unknown {
+    const obj: any = {};
+    if (message.fields) {
+      const entries = Object.entries(message.fields);
+      if (entries.length > 0) {
+        obj.fields = {};
+        entries.forEach(([k, v]) => {
+          obj.fields[k] = v;
+        });
+      }
+    }
+    return obj;
+  },
+
+  create<I extends Exact<DeepPartial<Struct>, I>>(base?: I): Struct {
+    return Struct.fromPartial(base ?? ({} as any));
+  },
+  fromPartial<I extends Exact<DeepPartial<Struct>, I>>(object: I): Struct {
+    const message = createBaseStruct();
+    message.fields = (object.fields === undefined || object.fields === null)
+      ? undefined
+      : Object.entries(object.fields ?? {}).reduce<{ [key: string]: any | undefined }>((acc, [key, value]) => {
+        if (value !== undefined) {
+          acc[key] = value;
+        }
+        return acc;
+      }, {});
+    return message;
+  },
+
+  wrap(object: { [key: string]: any } | undefined): Struct {
+    const struct = createBaseStruct();
+    struct.fields ??= {};
+    if (object !== undefined) {
+      for (const key of Object.keys(object)) {
+        struct.fields[key] = object[key];
+      }
+    }
+    return struct;
+  },
+
+  unwrap(message: Struct): { [key: string]: any } {
+    const object: { [key: string]: any } = {};
+    if (message.fields) {
+      for (const key of Object.keys(message.fields)) {
+        object[key] = message.fields[key];
+      }
+    }
+    return object;
+  },
+};
+
+function createBaseStruct_FieldsEntry(): Struct_FieldsEntry {
+  return { key: "" };
+}
+
+export const Struct_FieldsEntry = {
+  encode(message: Struct_FieldsEntry, writer: _m0.Writer = _m0.Writer.create()): _m0.Writer {
+    if (message.key !== "") {
+      writer.uint32(10).string(message.key);
+    }
+    if (message.value !== undefined) {
+      Value.encode(Value.wrap(message.value), writer.uint32(18).fork()).ldelim();
+    }
+    return writer;
+  },
+
+  decode(input: _m0.Reader | Uint8Array, length?: number): Struct_FieldsEntry {
+    const reader = input instanceof _m0.Reader ? input : _m0.Reader.create(input);
+    let end = length === undefined ? reader.len : reader.pos + length;
+    const message = createBaseStruct_FieldsEntry();
+    while (reader.pos < end) {
+      const tag = reader.uint32();
+      switch (tag >>> 3) {
+        case 1:
+          if (tag !== 10) {
+            break;
+          }
+
+          message.key = reader.string();
+          continue;
+        case 2:
+          if (tag !== 18) {
+            break;
+          }
+
+          message.value = Value.unwrap(Value.decode(reader, reader.uint32()));
+          continue;
+      }
+      if ((tag & 7) === 4 || tag === 0) {
+        break;
+      }
+      reader.skipType(tag & 7);
+    }
+    return message;
+  },
+
+  fromJSON(object: any): Struct_FieldsEntry {
+    return {
+      key: isSet(object.key) ? globalThis.String(object.key) : "",
+      value: isSet(object?.value) ? object.value : undefined,
+    };
+  },
+
+  toJSON(message: Struct_FieldsEntry): unknown {
+    const obj: any = {};
+    if (message.key !== "") {
+      obj.key = message.key;
+    }
+    if (message.value !== undefined) {
+      obj.value = message.value;
+    }
+    return obj;
+  },
+
+  create<I extends Exact<DeepPartial<Struct_FieldsEntry>, I>>(base?: I): Struct_FieldsEntry {
+    return Struct_FieldsEntry.fromPartial(base ?? ({} as any));
+  },
+  fromPartial<I extends Exact<DeepPartial<Struct_FieldsEntry>, I>>(object: I): Struct_FieldsEntry {
+    const message = createBaseStruct_FieldsEntry();
+    message.key = object.key ?? "";
+    message.value = object.value ?? undefined;
+    return message;
+  },
+};
+
+function createBaseValue(): Value {
+  return {};
+}
+
+export const Value = {
+  encode(message: Value, writer: _m0.Writer = _m0.Writer.create()): _m0.Writer {
+    if (message.nullValue !== undefined) {
+      writer.uint32(8).int32(message.nullValue);
+    }
+    if (message.numberValue !== undefined) {
+      writer.uint32(17).double(message.numberValue);
+    }
+    if (message.stringValue !== undefined) {
+      writer.uint32(26).string(message.stringValue);
+    }
+    if (message.boolValue !== undefined) {
+      writer.uint32(32).bool(message.boolValue);
+    }
+    if (message.structValue !== undefined) {
+      Struct.encode(Struct.wrap(message.structValue), writer.uint32(42).fork()).ldelim();
+    }
+    if (message.listValue !== undefined) {
+      ListValue.encode(ListValue.wrap(message.listValue), writer.uint32(50).fork()).ldelim();
+    }
+    return writer;
+  },
+
+  decode(input: _m0.Reader | Uint8Array, length?: number): Value {
+    const reader = input instanceof _m0.Reader ? input : _m0.Reader.create(input);
+    let end = length === undefined ? reader.len : reader.pos + length;
+    const message = createBaseValue();
+    while (reader.pos < end) {
+      const tag = reader.uint32();
+      switch (tag >>> 3) {
+        case 1:
+          if (tag !== 8) {
+            break;
+          }
+
+          message.nullValue = reader.int32() as any;
+          continue;
+        case 2:
+          if (tag !== 17) {
+            break;
+          }
+
+          message.numberValue = reader.double();
+          continue;
+        case 3:
+          if (tag !== 26) {
+            break;
+          }
+
+          message.stringValue = reader.string();
+          continue;
+        case 4:
+          if (tag !== 32) {
+            break;
+          }
+
+          message.boolValue = reader.bool();
+          continue;
+        case 5:
+          if (tag !== 42) {
+            break;
+          }
+
+          message.structValue = Struct.unwrap(Struct.decode(reader, reader.uint32()));
+          continue;
+        case 6:
+          if (tag !== 50) {
+            break;
+          }
+
+          message.listValue = ListValue.unwrap(ListValue.decode(reader, reader.uint32()));
+          continue;
+      }
+      if ((tag & 7) === 4 || tag === 0) {
+        break;
+      }
+      reader.skipType(tag & 7);
+    }
+    return message;
+  },
+
+  fromJSON(object: any): Value {
+    return {
+      nullValue: isSet(object.nullValue) ? nullValueFromJSON(object.nullValue) : undefined,
+      numberValue: isSet(object.numberValue) ? globalThis.Number(object.numberValue) : undefined,
+      stringValue: isSet(object.stringValue) ? globalThis.String(object.stringValue) : undefined,
+      boolValue: isSet(object.boolValue) ? globalThis.Boolean(object.boolValue) : undefined,
+      structValue: isObject(object.structValue) ? object.structValue : undefined,
+      listValue: globalThis.Array.isArray(object.listValue) ? [...object.listValue] : undefined,
+    };
+  },
+
+  toJSON(message: Value): unknown {
+    const obj: any = {};
+    if (message.nullValue !== undefined) {
+      obj.nullValue = nullValueToJSON(message.nullValue);
+    }
+    if (message.numberValue !== undefined) {
+      obj.numberValue = message.numberValue;
+    }
+    if (message.stringValue !== undefined) {
+      obj.stringValue = message.stringValue;
+    }
+    if (message.boolValue !== undefined) {
+      obj.boolValue = message.boolValue;
+    }
+    if (message.structValue !== undefined) {
+      obj.structValue = message.structValue;
+    }
+    if (message.listValue !== undefined) {
+      obj.listValue = message.listValue;
+    }
+    return obj;
+  },
+
+  create<I extends Exact<DeepPartial<Value>, I>>(base?: I): Value {
+    return Value.fromPartial(base ?? ({} as any));
+  },
+  fromPartial<I extends Exact<DeepPartial<Value>, I>>(object: I): Value {
+    const message = createBaseValue();
+    message.nullValue = object.nullValue ?? undefined;
+    message.numberValue = object.numberValue ?? undefined;
+    message.stringValue = object.stringValue ?? undefined;
+    message.boolValue = object.boolValue ?? undefined;
+    message.structValue = object.structValue ?? undefined;
+    message.listValue = object.listValue ?? undefined;
+    return message;
+  },
+
+  wrap(value: any): Value {
+    const result = createBaseValue();
+    if (value === null) {
+      result.nullValue = NullValue.NULL_VALUE;
+    } else if (typeof value === "boolean") {
+      result.boolValue = value;
+    } else if (typeof value === "number") {
+      result.numberValue = value;
+    } else if (typeof value === "string") {
+      result.stringValue = value;
+    } else if (globalThis.Array.isArray(value)) {
+      result.listValue = value;
+    } else if (typeof value === "object") {
+      result.structValue = value;
+    } else if (typeof value !== "undefined") {
+      throw new globalThis.Error("Unsupported any value type: " + typeof value);
+    }
+    return result;
+  },
+
+  unwrap(message: any): string | number | boolean | Object | null | Array<any> | undefined {
+    if (message.stringValue !== undefined) {
+      return message.stringValue;
+    } else if (message?.numberValue !== undefined) {
+      return message.numberValue;
+    } else if (message?.boolValue !== undefined) {
+      return message.boolValue;
+    } else if (message?.structValue !== undefined) {
+      return message.structValue as any;
+    } else if (message?.listValue !== undefined) {
+      return message.listValue;
+    } else if (message?.nullValue !== undefined) {
+      return null;
+    }
+    return undefined;
+  },
+};
+
+function createBaseListValue(): ListValue {
+  return {};
+}
+
+export const ListValue = {
+  encode(message: ListValue, writer: _m0.Writer = _m0.Writer.create()): _m0.Writer {
+    if (message.values !== undefined && message.values.length !== 0) {
+      for (const v of message.values) {
+        Value.encode(Value.wrap(v!), writer.uint32(10).fork()).ldelim();
+      }
+    }
+    return writer;
+  },
+
+  decode(input: _m0.Reader | Uint8Array, length?: number): ListValue {
+    const reader = input instanceof _m0.Reader ? input : _m0.Reader.create(input);
+    let end = length === undefined ? reader.len : reader.pos + length;
+    const message = createBaseListValue();
+    while (reader.pos < end) {
+      const tag = reader.uint32();
+      switch (tag >>> 3) {
+        case 1:
+          if (tag !== 10) {
+            break;
+          }
+
+          if (message.values === undefined) {
+            message.values = [];
+          }
+          message.values!.push(Value.unwrap(Value.decode(reader, reader.uint32())));
+          continue;
+      }
+      if ((tag & 7) === 4 || tag === 0) {
+        break;
+      }
+      reader.skipType(tag & 7);
+    }
+    return message;
+  },
+
+  fromJSON(object: any): ListValue {
+    return { values: globalThis.Array.isArray(object?.values) ? [...object.values] : [] };
+  },
+
+  toJSON(message: ListValue): unknown {
+    const obj: any = {};
+    if (message.values?.length) {
+      obj.values = message.values;
+    }
+    return obj;
+  },
+
+  create<I extends Exact<DeepPartial<ListValue>, I>>(base?: I): ListValue {
+    return ListValue.fromPartial(base ?? ({} as any));
+  },
+  fromPartial<I extends Exact<DeepPartial<ListValue>, I>>(object: I): ListValue {
+    const message = createBaseListValue();
+    message.values = object.values?.map((e) => e) || undefined;
+    return message;
+  },
+
+  wrap(array: Array<any> | undefined): ListValue {
+    const result = createBaseListValue();
+    result.values = array ?? [];
+    return result;
+  },
+
+  unwrap(message: ListValue): Array<any> {
+    if (message?.hasOwnProperty("values") && globalThis.Array.isArray(message.values)) {
+      return message.values;
+    } else {
+      return message as any;
+    }
+  },
+};
+
+type Builtin = Date | Function | Uint8Array | string | number | boolean | undefined;
+
+export type DeepPartial<T> = T extends Builtin ? T
+  : T extends globalThis.Array<infer U> ? globalThis.Array<DeepPartial<U>>
+  : T extends ReadonlyArray<infer U> ? ReadonlyArray<DeepPartial<U>>
+  : T extends {} ? { [K in keyof T]?: DeepPartial<T[K]> }
+  : Partial<T>;
+
+type KeysOfUnion<T> = T extends T ? keyof T : never;
+export type Exact<P, I extends P> = P extends Builtin ? P
+  : P & { [K in keyof P]: Exact<P[K], I[K]> } & { [K in Exclude<keyof I, KeysOfUnion<P>>]: never };
+
+function isObject(value: any): boolean {
+  return typeof value === "object" && value !== null;
+}
+
+function isSet(value: any): boolean {
+  return value !== null && value !== undefined;
+}
diff --git a/integration/use-optionals-no-undefined/test.bin b/integration/use-optionals-no-undefined/test.bin
index 11c02597f..b55039e57 100644
Binary files a/integration/use-optionals-no-undefined/test.bin and b/integration/use-optionals-no-undefined/test.bin differ
diff --git a/integration/use-optionals-no-undefined/test.proto b/integration/use-optionals-no-undefined/test.proto
index d752ce261..5a888b9c5 100644
--- a/integration/use-optionals-no-undefined/test.proto
+++ b/integration/use-optionals-no-undefined/test.proto
@@ -1,6 +1,8 @@
 syntax = "proto3";
 package optionalstest;
 
+import "google/protobuf/struct.proto";
+
 message OptionalsTest {
   int32 id = 1;
   Child child = 2;
@@ -27,6 +29,8 @@ message OptionalsTest {
   optional bytes opt_data = 27;
 
   map<string, string> translations = 30;
+  
+  google.protobuf.Struct struct = 32;
 }
 
 enum StateEnum {
diff --git a/integration/use-optionals-no-undefined/test.ts b/integration/use-optionals-no-undefined/test.ts
index 0cb49c2b9..a8ac8b164 100644
--- a/integration/use-optionals-no-undefined/test.ts
+++ b/integration/use-optionals-no-undefined/test.ts
@@ -1,5 +1,6 @@
 /* eslint-disable */
 import * as _m0 from "protobufjs/minimal";
+import { Struct } from "./google/protobuf/struct";
 import Long = require("long");
 
 export const protobufPackage = "optionalstest";
@@ -66,6 +67,7 @@ export interface OptionalsTest {
   optDescription?: string | undefined;
   optData?: Uint8Array | undefined;
   translations?: { [key: string]: string } | undefined;
+  struct?: { [key: string]: any } | undefined;
 }
 
 export interface OptionalsTest_TranslationsEntry {
@@ -170,6 +172,9 @@ export const OptionalsTest = {
     Object.entries(message.translations || {}).forEach(([key, value]) => {
       OptionalsTest_TranslationsEntry.encode({ key: key as any, value }, writer.uint32(242).fork()).ldelim();
     });
+    if (message.struct !== undefined) {
+      Struct.encode(Struct.wrap(message.struct), writer.uint32(258).fork()).ldelim();
+    }
     return writer;
   },
 
@@ -413,6 +418,13 @@ export const OptionalsTest = {
             message.translations![entry30.key] = entry30.value;
           }
           continue;
+        case 32:
+          if (tag !== 258) {
+            break;
+          }
+
+          message.struct = Struct.unwrap(Struct.decode(reader, reader.uint32()));
+          continue;
       }
       if ((tag & 7) === 4 || tag === 0) {
         break;
@@ -463,6 +475,7 @@ export const OptionalsTest = {
           return acc;
         }, {})
         : undefined,
+      struct: isObject(object.struct) ? object.struct : undefined,
     };
   },
 
@@ -540,6 +553,9 @@ export const OptionalsTest = {
         });
       }
     }
+    if (message.struct !== undefined) {
+      obj.struct = message.struct;
+    }
     return obj;
   },
 
@@ -579,6 +595,7 @@ export const OptionalsTest = {
         }
         return acc;
       }, {});
+    message.struct = object.struct ?? undefined;
     return message;
   },
 };
diff --git a/integration/use-readonly-types/google/protobuf/struct.ts b/integration/use-readonly-types/google/protobuf/struct.ts
index 1c1c45bca..83ef5f717 100644
--- a/integration/use-readonly-types/google/protobuf/struct.ts
+++ b/integration/use-readonly-types/google/protobuf/struct.ts
@@ -170,10 +170,11 @@ export const Struct = {
 
   wrap(object: { [key: string]: any } | undefined): Struct {
     const struct = createBaseStruct();
+
     if (object !== undefined) {
-      Object.keys(object).forEach((key) => {
+      for (const key of Object.keys(object)) {
         struct.fields[key] = object[key];
-      });
+      }
     }
     return struct;
   },
@@ -181,9 +182,9 @@ export const Struct = {
   unwrap(message: Struct): { [key: string]: any } {
     const object: { [key: string]: any } = {};
     if (message.fields) {
-      Object.keys(message.fields).forEach((key) => {
+      for (const key of Object.keys(message.fields)) {
         object[key] = message.fields[key];
-      });
+      }
     }
     return object;
   },
diff --git a/integration/value/google/protobuf/struct.ts b/integration/value/google/protobuf/struct.ts
index 5760ebc59..849206f64 100644
--- a/integration/value/google/protobuf/struct.ts
+++ b/integration/value/google/protobuf/struct.ts
@@ -184,10 +184,11 @@ export const Struct = {
 
   wrap(object: { [key: string]: any } | undefined): Struct {
     const struct = createBaseStruct();
+
     if (object !== undefined) {
-      Object.keys(object).forEach((key) => {
+      for (const key of Object.keys(object)) {
         struct.fields[key] = object[key];
-      });
+      }
     }
     return struct;
   },
@@ -195,9 +196,9 @@ export const Struct = {
   unwrap(message: Struct): { [key: string]: any } {
     const object: { [key: string]: any } = {};
     if (message.fields) {
-      Object.keys(message.fields).forEach((key) => {
+      for (const key of Object.keys(message.fields)) {
         object[key] = message.fields[key];
-      });
+      }
     }
     return object;
   },
diff --git a/src/generate-struct-wrappers.ts b/src/generate-struct-wrappers.ts
index bcf65d4d9..b08e08459 100644
--- a/src/generate-struct-wrappers.ts
+++ b/src/generate-struct-wrappers.ts
@@ -31,15 +31,20 @@ export function generateWrapDeep(ctx: Context, fullProtoTypeName: string, fieldN
   const chunks: Code[] = [];
   if (isStructTypeName(fullProtoTypeName)) {
     let setStatement = "struct.fields[key] = Value.wrap(object[key]);";
+    let defaultFields = "struct.fields ??= {};";
     if (ctx.options.useMapType) {
       setStatement = "struct.fields.set(key, Value.wrap(object[key]));";
+      defaultFields = "struct.fields ??= new Map<string, any | undefined>();";
     }
+    if (ctx.options.useOptionals !== "all") defaultFields = "";
+
     chunks.push(code`wrap(object: {[key: string]: any} | undefined): Struct {
       const struct = createBaseStruct();
+      ${defaultFields}
       if (object !== undefined) {
-        Object.keys(object).forEach(key => {
+        for (const key of Object.keys(object)) {
           ${setStatement}
-        });
+        }
       }
       return struct;
     }`);
@@ -99,18 +104,20 @@ export function generateUnwrapDeep(ctx: Context, fullProtoTypeName: string, fiel
     if (ctx.options.useMapType) {
       chunks.push(code`unwrap(message: Struct): {[key: string]: any} {
         const object: { [key: string]: any } = {};
-        [...message.fields.keys()].forEach((key) => {
-          object[key] = Value.unwrap(message.fields.get(key));
-        });
+        if (message.fields) {
+          for (const key of message.fields.keys()) {
+            object[key] = Value.unwrap(message.fields.get(key));
+          }
+        }
         return object;
       }`);
     } else {
       chunks.push(code`unwrap(message: Struct): {[key: string]: any} {
         const object: { [key: string]: any } = {};
         if (message.fields) {
-          Object.keys(message.fields).forEach(key => {
+          for (const key of Object.keys(message.fields)) {
             object[key] = Value.unwrap(message.fields[key]);
-          });
+          }
         }
         return object;
       }`);
@@ -165,15 +172,20 @@ export function generateWrapShallow(ctx: Context, fullProtoTypeName: string, fie
   const chunks: Code[] = [];
   if (isStructTypeName(fullProtoTypeName)) {
     let setStatement = "struct.fields[key] = object[key];";
+    let defaultFields = "struct.fields ??= {};";
     if (ctx.options.useMapType) {
       setStatement = "struct.fields.set(key, object[key]);";
+      defaultFields = "struct.fields ??= new Map<string, any | undefined>();";
     }
+    if (ctx.options.useOptionals !== "all") defaultFields = "";
+
     chunks.push(code`wrap(object: {[key: string]: any} | undefined): Struct {
       const struct = createBaseStruct();
+      ${defaultFields}
       if (object !== undefined) {
-        Object.keys(object).forEach(key => {
+        for (const key of Object.keys(object)) {
           ${setStatement}
-        });
+        }
       }
       return struct;
     }`);
@@ -254,18 +266,20 @@ export function generateUnwrapShallow(ctx: Context, fullProtoTypeName: string, f
     if (ctx.options.useMapType) {
       chunks.push(code`unwrap(message: Struct): {[key: string]: any} {
         const object: { [key: string]: any } = {};
-        [...message.fields.keys()].forEach((key) => {
-          object[key] = message.fields.get(key);
-        });
+        if (message.fields) {
+          for (const key of message.fields.keys()) {
+            object[key] = message.fields.get(key);
+          }
+        }
         return object;
       }`);
     } else {
       chunks.push(code`unwrap(message: Struct): {[key: string]: any} {
         const object: { [key: string]: any } = {};
         if (message.fields) {
-          Object.keys(message.fields).forEach(key => {
+          for (const key of Object.keys(message.fields)) {
             object[key] = message.fields[key];
-          });
+          }
         }
         return object;
       }`);