diff --git a/integration/generic-metadata/hero.ts b/integration/generic-metadata/hero.ts
index 8f4cf2943..f8ec71b31 100644
--- a/integration/generic-metadata/hero.ts
+++ b/integration/generic-metadata/hero.ts
@@ -1,8 +1,8 @@
 /* eslint-disable */
+import { Metadata } from "@grpc/grpc-js";
 import * as _m0 from "protobufjs/minimal";
 import { Observable } from "rxjs";
 import { map } from "rxjs/operators";
-import { Foo } from "./some-file";
 
 export const protobufPackage = "hero";
 
@@ -287,9 +287,9 @@ export const Villain = {
 };
 
 export interface HeroService {
-  FindOneHero(request: HeroById, metadata?: Foo): Promise<Hero>;
-  FindOneVillain(request: VillainById, metadata?: Foo): Promise<Villain>;
-  FindManyVillain(request: Observable<VillainById>, metadata?: Foo): Observable<Villain>;
+  FindOneHero(request: HeroById, metadata?: Metadata): Promise<Hero>;
+  FindOneVillain(request: VillainById, metadata?: Metadata): Promise<Villain>;
+  FindManyVillain(request: Observable<VillainById>, metadata?: Metadata): Observable<Villain>;
 }
 
 export const HeroServiceServiceName = "hero.HeroService";
@@ -303,21 +303,21 @@ export class HeroServiceClientImpl implements HeroService {
     this.FindOneVillain = this.FindOneVillain.bind(this);
     this.FindManyVillain = this.FindManyVillain.bind(this);
   }
-  FindOneHero(request: HeroById): Promise<Hero> {
+  FindOneHero(request: HeroById, metadata?: Metadata): Promise<Hero> {
     const data = HeroById.encode(request).finish();
-    const promise = this.rpc.request(this.service, "FindOneHero", data);
+    const promise = this.rpc.request(this.service, "FindOneHero", data, metadata);
     return promise.then((data) => Hero.decode(_m0.Reader.create(data)));
   }
 
-  FindOneVillain(request: VillainById): Promise<Villain> {
+  FindOneVillain(request: VillainById, metadata?: Metadata): Promise<Villain> {
     const data = VillainById.encode(request).finish();
-    const promise = this.rpc.request(this.service, "FindOneVillain", data);
+    const promise = this.rpc.request(this.service, "FindOneVillain", data, metadata);
     return promise.then((data) => Villain.decode(_m0.Reader.create(data)));
   }
 
-  FindManyVillain(request: Observable<VillainById>): Observable<Villain> {
+  FindManyVillain(request: Observable<VillainById>, metadata?: Metadata): Observable<Villain> {
     const data = request.pipe(map((request) => VillainById.encode(request).finish()));
-    const result = this.rpc.bidirectionalStreamingRequest(this.service, "FindManyVillain", data);
+    const result = this.rpc.bidirectionalStreamingRequest(this.service, "FindManyVillain", data, metadata);
     return result.pipe(map((data) => Villain.decode(_m0.Reader.create(data))));
   }
 }
@@ -355,10 +355,25 @@ export const HeroServiceDefinition = {
 } as const;
 
 interface Rpc {
-  request(service: string, method: string, data: Uint8Array): Promise<Uint8Array>;
-  clientStreamingRequest(service: string, method: string, data: Observable<Uint8Array>): Promise<Uint8Array>;
-  serverStreamingRequest(service: string, method: string, data: Uint8Array): Observable<Uint8Array>;
-  bidirectionalStreamingRequest(service: string, method: string, data: Observable<Uint8Array>): Observable<Uint8Array>;
+  request(service: string, method: string, data: Uint8Array, metadata?: Metadata): Promise<Uint8Array>;
+  clientStreamingRequest(
+    service: string,
+    method: string,
+    data: Observable<Uint8Array>,
+    metadata?: Metadata,
+  ): Promise<Uint8Array>;
+  serverStreamingRequest(
+    service: string,
+    method: string,
+    data: Uint8Array,
+    metadata?: Metadata,
+  ): Observable<Uint8Array>;
+  bidirectionalStreamingRequest(
+    service: string,
+    method: string,
+    data: Observable<Uint8Array>,
+    metadata?: Metadata,
+  ): Observable<Uint8Array>;
 }
 
 type Builtin = Date | Function | Uint8Array | string | number | boolean | undefined;
diff --git a/integration/generic-metadata/parameters.txt b/integration/generic-metadata/parameters.txt
index 187042c7d..fad3458b6 100644
--- a/integration/generic-metadata/parameters.txt
+++ b/integration/generic-metadata/parameters.txt
@@ -1 +1 @@
-metadataType=Foo@./some-file,outputServices=generic-definitions,outputServices=default
\ No newline at end of file
+metadataType=Foo@./some-file,outputServices=generic-definitions,outputServices=default,addGrpcMetadata=true
\ No newline at end of file
diff --git a/src/generate-services.ts b/src/generate-services.ts
index 3d67342fa..4b5d3696f 100644
--- a/src/generate-services.ts
+++ b/src/generate-services.ts
@@ -68,8 +68,7 @@ export function generateService(
       params.push(code`metadata?: grpc.Metadata`);
     } else if (options.addGrpcMetadata) {
       const Metadata = imp("Metadata@@grpc/grpc-js");
-      const q = options.addNestjsRestParameter ? "" : "?";
-      params.push(code`metadata${q}: ${Metadata}`);
+      params.push(code`metadata?: ${Metadata}`);
     } else if (options.metadataType) {
       const Metadata = imp(options.metadataType);
       params.push(code`metadata?: ${Metadata}`);
@@ -116,9 +115,11 @@ function generateRegularRpcMethod(ctx: Context, methodDesc: MethodDescriptorProt
   const params = [
     ...(options.context ? [code`ctx: Context`] : []),
     code`request: ${inputType}`,
+    ...(options.addGrpcMetadata ? [code`metadata?: Metadata`] : []),
     ...(options.useAbortSignal ? [code`abortSignal?: AbortSignal`] : []),
   ];
   const maybeCtx = options.context ? "ctx," : "";
+  const maybeMetadata = options.addGrpcMetadata ? "metadata," : "";
   const maybeAbortSignal = options.useAbortSignal ? "abortSignal || undefined," : "";
 
   let errorHandler;
@@ -193,6 +194,7 @@ function generateRegularRpcMethod(ctx: Context, methodDesc: MethodDescriptorProt
         this.service,
         "${methodDesc.name}",
         data,
+        ${maybeMetadata}
         ${maybeAbortSignal}
       );
       return ${returnStatement};
@@ -418,6 +420,7 @@ export function generateRpcType(ctx: Context, hasStreamingMethods: boolean): Cod
   const { options } = ctx;
   const maybeContext = options.context ? "<Context>" : "";
   const maybeContextParam = options.context ? "ctx: Context," : "";
+  const maybeMetadataParam = options.addGrpcMetadata ? `metadata?: Metadata,` : "";
   const maybeAbortSignalParam = options.useAbortSignal ? "abortSignal?: AbortSignal," : "";
   const methods = [[code`request`, code`Uint8Array`, code`Promise<Uint8Array>`]];
   const additionalMethods = [];
@@ -456,6 +459,7 @@ export function generateRpcType(ctx: Context, hasStreamingMethods: boolean): Cod
         service: string,
         method: string,
         data: ${method[1]},
+        ${maybeMetadataParam}
         ${maybeAbortSignalParam}
       ): ${method[2]};`);
   });