diff --git a/examples/gen-ios/objectivec/TypewriterExample/Analytics/SEGKicksAppAnalytics.h b/examples/gen-ios/objectivec/TypewriterExample/Analytics/SEGKicksAppAnalytics.h
index 124cb62a..ca64b4d7 100644
--- a/examples/gen-ios/objectivec/TypewriterExample/Analytics/SEGKicksAppAnalytics.h
+++ b/examples/gen-ios/objectivec/TypewriterExample/Analytics/SEGKicksAppAnalytics.h
@@ -25,22 +25,22 @@ NS_ASSUME_NONNULL_BEGIN
 /// Currency code associated with the transaction
 @property (nonatomic, nullable, copy) NSString *currency;
 /// Total discount associated with the transaction
-@property (nonatomic, nullable, assign) NSNumber *discount;
+@property (nonatomic, nullable, copy) NSNumber *discount;
 /// Order/transaction ID
 @property (nonatomic, copy) NSString *orderID;
 /// Products in the order
 @property (nonatomic, nullable, copy) NSArray<SEGProduct *> *products;
 /// Revenue associated with the transaction (excluding shipping and tax)
-@property (nonatomic, nullable, assign) NSNumber *revenue;
+@property (nonatomic, nullable, copy) NSNumber *revenue;
 /// Shipping cost associated with the transaction
-@property (nonatomic, nullable, assign) NSNumber *shipping;
+@property (nonatomic, nullable, copy) NSNumber *shipping;
 /// Total tax associated with the transaction
-@property (nonatomic, nullable, assign) NSNumber *tax;
+@property (nonatomic, nullable, copy) NSNumber *tax;
 /// Revenue with discounts and coupons added in. Note that our Google Analytics Ecommerce
 /// destination accepts total or revenue, but not both. For better flexibility and total
 /// control over tracking, we let you decide how to calculate how coupons and discounts are
 /// applied
-@property (nonatomic, nullable, assign) NSNumber *total;
+@property (nonatomic, nullable, copy) NSNumber *total;
 @end
 
 typedef void (^ SEGOrderCompletedBuilderBlock)(SEGOrderCompletedBuilder *);
@@ -55,22 +55,22 @@ typedef void (^ SEGOrderCompletedBuilderBlock)(SEGOrderCompletedBuilder *);
 /// Currency code associated with the transaction
 @property (nonatomic, nullable, copy) NSString *currency;
 /// Total discount associated with the transaction
-@property (nonatomic, nullable, assign) NSNumber *discount;
+@property (nonatomic, nullable, copy) NSNumber *discount;
 /// Order/transaction ID
 @property (nonatomic, copy) NSString *orderID;
 /// Products in the order
 @property (nonatomic, nullable, copy) NSArray<SEGProduct *> *products;
 /// Revenue associated with the transaction (excluding shipping and tax)
-@property (nonatomic, nullable, assign) NSNumber *revenue;
+@property (nonatomic, nullable, copy) NSNumber *revenue;
 /// Shipping cost associated with the transaction
-@property (nonatomic, nullable, assign) NSNumber *shipping;
+@property (nonatomic, nullable, copy) NSNumber *shipping;
 /// Total tax associated with the transaction
-@property (nonatomic, nullable, assign) NSNumber *tax;
+@property (nonatomic, nullable, copy) NSNumber *tax;
 /// Revenue with discounts and coupons added in. Note that our Google Analytics Ecommerce
 /// destination accepts total or revenue, but not both. For better flexibility and total
 /// control over tracking, we let you decide how to calculate how coupons and discounts are
 /// applied
-@property (nonatomic, nullable, assign) NSNumber *total;
+@property (nonatomic, nullable, copy) NSNumber *total;
 @end
 
 @interface SEGProduct : NSObject
@@ -85,13 +85,13 @@ typedef void (^ SEGOrderCompletedBuilderBlock)(SEGOrderCompletedBuilder *);
 /// Name of the product being viewed
 @property (nonatomic, nullable, copy) NSString *name;
 /// Position in the product list (ex. 3)
-@property (nonatomic, nullable, assign) NSNumber *position;
+@property (nonatomic, nullable, copy) NSNumber *position;
 /// Price of the product being viewed
-@property (nonatomic, nullable, assign) NSNumber *price;
+@property (nonatomic, nullable, copy) NSNumber *price;
 /// Database id of the product being viewed
 @property (nonatomic, nullable, copy) NSString *productID;
 /// Quantity of a product
-@property (nonatomic, nullable, assign) NSNumber *quantity;
+@property (nonatomic, nullable, copy) NSNumber *quantity;
 /// Sku of the product being viewed
 @property (nonatomic, nullable, copy) NSString *sku;
 /// URL of the product page
@@ -114,13 +114,13 @@ typedef void (^ SEGProductBuilderBlock)(SEGProductBuilder *);
 /// Name of the product being viewed
 @property (nonatomic, nullable, copy) NSString *name;
 /// Position in the product list (ex. 3)
-@property (nonatomic, nullable, assign) NSNumber *position;
+@property (nonatomic, nullable, copy) NSNumber *position;
 /// Price of the product being viewed
-@property (nonatomic, nullable, assign) NSNumber *price;
+@property (nonatomic, nullable, copy) NSNumber *price;
 /// Database id of the product being viewed
 @property (nonatomic, nullable, copy) NSString *productID;
 /// Quantity of a product
-@property (nonatomic, nullable, assign) NSNumber *quantity;
+@property (nonatomic, nullable, copy) NSNumber *quantity;
 /// Sku of the product being viewed
 @property (nonatomic, nullable, copy) NSString *sku;
 /// URL of the product page
diff --git a/package.json b/package.json
index 8bf1ec44..0d00ada1 100644
--- a/package.json
+++ b/package.json
@@ -39,7 +39,6 @@
   "scripts": {
     "start": "node ./dist/src/index.js",
     "test": "jest",
-    "update-snapshots": "jest -u",
     "watch": "tsc -w",
     "build": "rm -rf dist && tsc",
     "prepare": "yarn run build",
diff --git a/src/commands/gen-ios.ts b/src/commands/gen-ios.ts
index caaa7216..2091bbbc 100644
--- a/src/commands/gen-ios.ts
+++ b/src/commands/gen-ios.ts
@@ -9,11 +9,12 @@ import {
   Name,
   Sourcelike,
   Type,
-  ObjectType
+  ObjectType,
+  matchType
 } from 'quicktype-core'
 import { stringEscape } from 'quicktype-core/dist/support/Strings'
 import { OptionValues, StringOption } from 'quicktype-core/dist/RendererOptions'
-import { objcOptions } from 'quicktype-core/dist/language/Objective-C'
+import { objcOptions, MemoryAttribute } from 'quicktype-core/dist/language/Objective-C'
 
 import {
   getTypedTrackHandler,
@@ -564,9 +565,35 @@ class AnalyticsObjectiveCWrapperRenderer extends ObjectiveCRenderer {
     })
   }
 
+  /**
+   * Always used the boxed types, because of a potential upstream bu with nullable values
+   * in QuickType. We need to use a boxed type if we make attach the `nullable` property modifier.
+   */
   protected objcType(t: Type, _: boolean): [Sourcelike, string] {
     return super.objcType(t, true)
   }
+
+  /**
+   * Override memoryAttribute in order to replace assign with copy for numeric types.
+   *
+   * Defer to QuickType for all other types.
+   */
+  protected memoryAttribute(t: Type, isNullable: boolean): MemoryAttribute {
+    return matchType<MemoryAttribute>(
+      t,
+      anyType => super.memoryAttribute(t, isNullable),
+      nullType => super.memoryAttribute(t, isNullable),
+      boolType => super.memoryAttribute(t, isNullable),
+      integerType => (isNullable ? 'strong' : 'copy'),
+      doubleType => (isNullable ? 'strong' : 'copy'),
+      stringType => super.memoryAttribute(t, isNullable),
+      arrayType => super.memoryAttribute(t, isNullable),
+      classType => super.memoryAttribute(t, isNullable),
+      mapType => super.memoryAttribute(t, isNullable),
+      enumType => super.memoryAttribute(t, isNullable),
+      unionType => super.memoryAttribute(t, isNullable)
+    )
+  }
 }
 
 export async function genObjC(events: TrackedEvent[], { trackingPlan, classPrefix }: Params) {
diff --git a/tests/commands/gen-ios/__snapshots__/SEGTestTrackingPlanAnalytics.h b/tests/commands/gen-ios/__snapshots__/SEGTestTrackingPlanAnalytics.h
index 8bc4f6f3..abc6a731 100644
--- a/tests/commands/gen-ios/__snapshots__/SEGTestTrackingPlanAnalytics.h
+++ b/tests/commands/gen-ios/__snapshots__/SEGTestTrackingPlanAnalytics.h
@@ -53,11 +53,11 @@ typedef void (^ SEGThe42_TerribleEventName3BuilderBlock)(SEGThe42_TerribleEventN
 /// Optional boolean property
 @property (nonatomic, nullable, assign) NSNumber *isOptionalBoolean;
 /// Optional integer property
-@property (nonatomic, nullable, assign) NSNumber *optionalInt;
-@property (nonatomic, nullable, copy)   NSString *optionalNullableString;
+@property (nonatomic, nullable, copy) NSNumber *optionalInt;
+@property (nonatomic, nullable, copy) NSString *optionalNullableString;
 /// Optional number property
-@property (nonatomic, nullable, assign) NSNumber *optionalNumber;
-@property (nonatomic, nullable, copy)   id optionalNumberOrString;
+@property (nonatomic, nullable, copy) NSNumber *optionalNumber;
+@property (nonatomic, nullable, copy) id optionalNumberOrString;
 /// Optional object property
 @property (nonatomic, nullable, strong) SEGOptionalObject *optionalObject;
 /// Optional object (empty) property
@@ -75,11 +75,11 @@ typedef void (^ SEGThe42_TerribleEventName3BuilderBlock)(SEGThe42_TerribleEventN
 /// Required boolean property
 @property (nonatomic, assign) NSNumber *isRequiredBoolean;
 /// Required integer property
-@property (nonatomic, assign) NSNumber *requiredInt;
-@property (nonatomic, copy)   NSString *requiredNullableString;
+@property (nonatomic, copy) NSNumber *requiredInt;
+@property (nonatomic, copy) NSString *requiredNullableString;
 /// Required number property
-@property (nonatomic, assign) NSNumber *requiredNumber;
-@property (nonatomic, copy)   id requiredNumberOrString;
+@property (nonatomic, copy) NSNumber *requiredNumber;
+@property (nonatomic, copy) id requiredNumberOrString;
 /// Required object property
 @property (nonatomic, strong) SEGRequiredObject *requiredObject;
 /// Required object (empty) property
@@ -102,11 +102,11 @@ typedef void (^ SEGExampleEventBuilderBlock)(SEGExampleEventBuilder *);
 /// Optional boolean property
 @property (nonatomic, nullable, assign) NSNumber *isOptionalBoolean;
 /// Optional integer property
-@property (nonatomic, nullable, assign) NSNumber *optionalInt;
-@property (nonatomic, nullable, copy)   NSString *optionalNullableString;
+@property (nonatomic, nullable, copy) NSNumber *optionalInt;
+@property (nonatomic, nullable, copy) NSString *optionalNullableString;
 /// Optional number property
-@property (nonatomic, nullable, assign) NSNumber *optionalNumber;
-@property (nonatomic, nullable, copy)   id optionalNumberOrString;
+@property (nonatomic, nullable, copy) NSNumber *optionalNumber;
+@property (nonatomic, nullable, copy) id optionalNumberOrString;
 /// Optional object property
 @property (nonatomic, nullable, strong) SEGOptionalObject *optionalObject;
 /// Optional object (empty) property
@@ -124,11 +124,11 @@ typedef void (^ SEGExampleEventBuilderBlock)(SEGExampleEventBuilder *);
 /// Required boolean property
 @property (nonatomic, assign) NSNumber *isRequiredBoolean;
 /// Required integer property
-@property (nonatomic, assign) NSNumber *requiredInt;
-@property (nonatomic, copy)   NSString *requiredNullableString;
+@property (nonatomic, copy) NSNumber *requiredInt;
+@property (nonatomic, copy) NSString *requiredNullableString;
 /// Required number property
-@property (nonatomic, assign) NSNumber *requiredNumber;
-@property (nonatomic, copy)   id requiredNumberOrString;
+@property (nonatomic, copy) NSNumber *requiredNumber;
+@property (nonatomic, copy) id requiredNumberOrString;
 /// Required object property
 @property (nonatomic, strong) SEGRequiredObject *requiredObject;
 /// Required object (empty) property
diff --git a/yarn.lock b/yarn.lock
index fcb4f384..f15eb209 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -4056,9 +4056,9 @@ js-tokens@^3.0.2:
   integrity sha1-mGbfOVECEw449/mWvOtlRDIJwls=
 
 js-yaml@^3.12.0, js-yaml@^3.7.0, js-yaml@^3.9.0:
-  version "3.12.0"
-  resolved "https://registry.yarnpkg.com/js-yaml/-/js-yaml-3.12.0.tgz#eaed656ec8344f10f527c6bfa1b6e2244de167d1"
-  integrity sha512-PIt2cnwmPfL4hKNwqeiuz4bKfnzHTBv6HyVgjahA6mPLwPDzjDWrplJBMjHUFxku/N3FlmrbyPclad+I+4mJ3A==
+  version "3.13.1"
+  resolved "https://registry.yarnpkg.com/js-yaml/-/js-yaml-3.13.1.tgz#aff151b30bfdfa8e49e05da22e7415e9dfa37847"
+  integrity sha512-YfbcO7jXDdyj0DGxYVSlSeQNHbD7XPWvrVWeVUujrQEoZzWJIRrCPoyk6kL6IAjAG2IolMK4T0hNUe0HOUs5Jw==
   dependencies:
     argparse "^1.0.7"
     esprima "^4.0.0"