diff --git a/packages/assets-registry/registry.js b/packages/assets-registry/registry.js
index 435bd519411f..d193d3af1c87 100644
--- a/packages/assets-registry/registry.js
+++ b/packages/assets-registry/registry.js
@@ -14,16 +14,16 @@
 export type AssetDestPathResolver = 'android' | 'generic';
 
 export type PackagerAsset = {
-  +__packager_asset: boolean,
-  +fileSystemLocation: string,
-  +httpServerLocation: string,
-  +width: ?number,
-  +height: ?number,
-  +scales: Array<number>,
-  +hash: string,
-  +name: string,
-  +type: string,
-  +resolver?: AssetDestPathResolver,
+  readonly __packager_asset: boolean,
+  readonly fileSystemLocation: string,
+  readonly httpServerLocation: string,
+  readonly width: ?number,
+  readonly height: ?number,
+  readonly scales: Array<number>,
+  readonly hash: string,
+  readonly name: string,
+  readonly type: string,
+  readonly resolver?: AssetDestPathResolver,
   ...
 };
 */
diff --git a/packages/dev-middleware/src/inspector-proxy/types.js b/packages/dev-middleware/src/inspector-proxy/types.js
index 8d95b8554517..89838f2d11d0 100644
--- a/packages/dev-middleware/src/inspector-proxy/types.js
+++ b/packages/dev-middleware/src/inspector-proxy/types.js
@@ -162,5 +162,5 @@ export type DeepReadOnly<T> =
   T extends ReadonlyArray<infer V>
     ? ReadonlyArray<DeepReadOnly<V>>
     : T extends {...}
-      ? {+[K in keyof T]: DeepReadOnly<T[K]>}
+      ? {readonly [K in keyof T]: DeepReadOnly<T[K]>}
       : T;
diff --git a/packages/react-native-codegen/e2e/deep_imports/__test_fixtures__/modules/NativeArrayTurboModule.js b/packages/react-native-codegen/e2e/deep_imports/__test_fixtures__/modules/NativeArrayTurboModule.js
index d044949283e3..71da1584be86 100644
--- a/packages/react-native-codegen/e2e/deep_imports/__test_fixtures__/modules/NativeArrayTurboModule.js
+++ b/packages/react-native-codegen/e2e/deep_imports/__test_fixtures__/modules/NativeArrayTurboModule.js
@@ -16,9 +16,12 @@ export type ArrayType = string;
 type AnotherArray = Array<ArrayType>;
 
 export interface Spec extends TurboModule {
-  +getArray: (a: Array<any>) => Array<string>;
-  +getReadOnlyArray: (a: Array<any>) => ReadonlyArray<string>;
-  +getArrayWithAlias: (a: AnotherArray, b: Array<ArrayType>) => AnotherArray;
+  readonly getArray: (a: Array<any>) => Array<string>;
+  readonly getReadOnlyArray: (a: Array<any>) => ReadonlyArray<string>;
+  readonly getArrayWithAlias: (
+    a: AnotherArray,
+    b: Array<ArrayType>,
+  ) => AnotherArray;
 }
 
 export default TurboModuleRegistry.getEnforcing<Spec>(
diff --git a/packages/react-native-codegen/e2e/deep_imports/__test_fixtures__/modules/NativeBooleanTurboModule.js b/packages/react-native-codegen/e2e/deep_imports/__test_fixtures__/modules/NativeBooleanTurboModule.js
index 7666fe80dd77..af8166072de6 100644
--- a/packages/react-native-codegen/e2e/deep_imports/__test_fixtures__/modules/NativeBooleanTurboModule.js
+++ b/packages/react-native-codegen/e2e/deep_imports/__test_fixtures__/modules/NativeBooleanTurboModule.js
@@ -16,8 +16,8 @@ export type Boolean = boolean;
 type AnotherBoolean = Boolean;
 
 export interface Spec extends TurboModule {
-  +getBoolean: (arg: boolean) => boolean;
-  +getBooleanWithAlias: (arg: Boolean) => AnotherBoolean;
+  readonly getBoolean: (arg: boolean) => boolean;
+  readonly getBooleanWithAlias: (arg: Boolean) => AnotherBoolean;
 }
 
 export default TurboModuleRegistry.getEnforcing<Spec>(
diff --git a/packages/react-native-codegen/e2e/deep_imports/__test_fixtures__/modules/NativeCallbackTurboModule.js b/packages/react-native-codegen/e2e/deep_imports/__test_fixtures__/modules/NativeCallbackTurboModule.js
index 943cd5d404b3..745966dca775 100644
--- a/packages/react-native-codegen/e2e/deep_imports/__test_fixtures__/modules/NativeCallbackTurboModule.js
+++ b/packages/react-native-codegen/e2e/deep_imports/__test_fixtures__/modules/NativeCallbackTurboModule.js
@@ -16,8 +16,8 @@ export type String = string;
 type CB = (value: String) => void;
 
 export interface Spec extends TurboModule {
-  +getValueWithCallback: (callback: (value: string) => void) => void;
-  +getValueWithCallbackWithAlias: (c: CB) => void;
+  readonly getValueWithCallback: (callback: (value: string) => void) => void;
+  readonly getValueWithCallbackWithAlias: (c: CB) => void;
 }
 
 export default TurboModuleRegistry.getEnforcing<Spec>(
diff --git a/packages/react-native-codegen/e2e/deep_imports/__test_fixtures__/modules/NativeEnumTurboModule.js b/packages/react-native-codegen/e2e/deep_imports/__test_fixtures__/modules/NativeEnumTurboModule.js
index e2918fb7556d..bd7370864231 100644
--- a/packages/react-native-codegen/e2e/deep_imports/__test_fixtures__/modules/NativeEnumTurboModule.js
+++ b/packages/react-native-codegen/e2e/deep_imports/__test_fixtures__/modules/NativeEnumTurboModule.js
@@ -49,17 +49,17 @@ export type StateTypeWithEnums = {
 };
 
 export interface Spec extends TurboModule {
-  +getStatusRegular: (statusProp: StateType) => StatusRegularEnum;
-  +getStatusStr: (statusProp: StateType) => StatusStrEnum;
-  +getStatusNum: (statusProp: StateType) => StatusNumEnum;
-  +getStatusLowerCase: (statusProp: StateType) => StatusLowerCaseEnum;
-  +getStateType: (
+  readonly getStatusRegular: (statusProp: StateType) => StatusRegularEnum;
+  readonly getStatusStr: (statusProp: StateType) => StatusStrEnum;
+  readonly getStatusNum: (statusProp: StateType) => StatusNumEnum;
+  readonly getStatusLowerCase: (statusProp: StateType) => StatusLowerCaseEnum;
+  readonly getStateType: (
     a: StatusRegularEnum,
     b: StatusStrEnum,
     c: StatusNumEnum,
     d: StatusLowerCaseEnum,
   ) => StateType;
-  +getStateTypeWithEnums: (
+  readonly getStateTypeWithEnums: (
     paramOfTypeWithEnums: StateTypeWithEnums,
   ) => StateTypeWithEnums;
 }
diff --git a/packages/react-native-codegen/e2e/deep_imports/__test_fixtures__/modules/NativeNullableTurboModule.js b/packages/react-native-codegen/e2e/deep_imports/__test_fixtures__/modules/NativeNullableTurboModule.js
index b2a8d69dacb7..d586369ad556 100644
--- a/packages/react-native-codegen/e2e/deep_imports/__test_fixtures__/modules/NativeNullableTurboModule.js
+++ b/packages/react-native-codegen/e2e/deep_imports/__test_fixtures__/modules/NativeNullableTurboModule.js
@@ -13,12 +13,12 @@ import type {TurboModule} from 'react-native/Libraries/TurboModule/RCTExport';
 import * as TurboModuleRegistry from 'react-native/Libraries/TurboModule/TurboModuleRegistry';
 
 export interface Spec extends TurboModule {
-  +getBool: (a: ?boolean) => ?boolean;
-  +getNumber: (a: ?number) => ?number;
-  +getString: (a: ?number) => ?string;
-  +getArray: (a: ?Array<any>) => ?Array<any>;
-  +getObject: (a: ?Object) => ?Object;
-  +getValueWithPromise: () => ?Promise<string>;
+  readonly getBool: (a: ?boolean) => ?boolean;
+  readonly getNumber: (a: ?number) => ?number;
+  readonly getString: (a: ?number) => ?string;
+  readonly getArray: (a: ?Array<any>) => ?Array<any>;
+  readonly getObject: (a: ?Object) => ?Object;
+  readonly getValueWithPromise: () => ?Promise<string>;
 }
 
 export default TurboModuleRegistry.getEnforcing<Spec>(
diff --git a/packages/react-native-codegen/e2e/deep_imports/__test_fixtures__/modules/NativeNumberTurboModule.js b/packages/react-native-codegen/e2e/deep_imports/__test_fixtures__/modules/NativeNumberTurboModule.js
index ddbf1ef0532e..9754aa73bdd5 100644
--- a/packages/react-native-codegen/e2e/deep_imports/__test_fixtures__/modules/NativeNumberTurboModule.js
+++ b/packages/react-native-codegen/e2e/deep_imports/__test_fixtures__/modules/NativeNumberTurboModule.js
@@ -16,8 +16,8 @@ export type Number = number;
 type AnotherNumber = Number;
 
 export interface Spec extends TurboModule {
-  +getNumber: (arg: number) => number;
-  +getNumberWithAlias: (arg: Number) => AnotherNumber;
+  readonly getNumber: (arg: number) => number;
+  readonly getNumberWithAlias: (arg: Number) => AnotherNumber;
 }
 
 export default TurboModuleRegistry.getEnforcing<Spec>(
diff --git a/packages/react-native-codegen/e2e/deep_imports/__test_fixtures__/modules/NativeObjectTurboModule.js b/packages/react-native-codegen/e2e/deep_imports/__test_fixtures__/modules/NativeObjectTurboModule.js
index b0967fea6f34..39b171ee3d37 100644
--- a/packages/react-native-codegen/e2e/deep_imports/__test_fixtures__/modules/NativeObjectTurboModule.js
+++ b/packages/react-native-codegen/e2e/deep_imports/__test_fixtures__/modules/NativeObjectTurboModule.js
@@ -16,10 +16,12 @@ export type GenericObject = Object;
 type AnotherGenericObject = GenericObject;
 
 export interface Spec extends TurboModule {
-  +getGenericObject: (arg: Object) => Object;
-  +getGenericObjectReadOnly: (arg: Object) => Readonly<{a: string}>;
-  +getGenericObjectWithAlias: (arg: GenericObject) => AnotherGenericObject;
-  +difficultObject: (A: {
+  readonly getGenericObject: (arg: Object) => Object;
+  readonly getGenericObjectReadOnly: (arg: Object) => Readonly<{a: string}>;
+  readonly getGenericObjectWithAlias: (
+    arg: GenericObject,
+  ) => AnotherGenericObject;
+  readonly difficultObject: (A: {
     D: boolean,
     E: {
       D: boolean,
@@ -40,7 +42,7 @@ export interface Spec extends TurboModule {
     },
     F: string,
   };
-  +getConstants: () => {
+  readonly getConstants: () => {
     D: boolean,
     E: {
       D: boolean,
diff --git a/packages/react-native-codegen/e2e/deep_imports/__test_fixtures__/modules/NativeOptionalObjectTurboModule.js b/packages/react-native-codegen/e2e/deep_imports/__test_fixtures__/modules/NativeOptionalObjectTurboModule.js
index a08851e37d0f..a8c4dd18c4d8 100644
--- a/packages/react-native-codegen/e2e/deep_imports/__test_fixtures__/modules/NativeOptionalObjectTurboModule.js
+++ b/packages/react-native-codegen/e2e/deep_imports/__test_fixtures__/modules/NativeOptionalObjectTurboModule.js
@@ -13,7 +13,7 @@ import type {TurboModule} from 'react-native/Libraries/TurboModule/RCTExport';
 import * as TurboModuleRegistry from 'react-native/Libraries/TurboModule/TurboModuleRegistry';
 
 export interface Spec extends TurboModule {
-  +getConstants: () => {
+  readonly getConstants: () => {
     D?: ?boolean,
     A?: Array<any>,
     E?: ?{
diff --git a/packages/react-native-codegen/e2e/deep_imports/__test_fixtures__/modules/NativePartialAnnotationTurboModule.js b/packages/react-native-codegen/e2e/deep_imports/__test_fixtures__/modules/NativePartialAnnotationTurboModule.js
index eadaef861a98..7e8718733ba0 100644
--- a/packages/react-native-codegen/e2e/deep_imports/__test_fixtures__/modules/NativePartialAnnotationTurboModule.js
+++ b/packages/react-native-codegen/e2e/deep_imports/__test_fixtures__/modules/NativePartialAnnotationTurboModule.js
@@ -22,10 +22,10 @@ export type SomeObj = {
 export type PartialSomeObj = Partial<SomeObj>;
 
 export interface Spec extends TurboModule {
-  +getSomeObj: () => SomeObj;
-  +getPartialSomeObj: () => Partial<SomeObj>;
-  +getSomeObjFromPartialSomeObj: (value: Partial<SomeObj>) => SomeObj;
-  +getPartialPartial: (
+  readonly getSomeObj: () => SomeObj;
+  readonly getPartialSomeObj: () => Partial<SomeObj>;
+  readonly getSomeObjFromPartialSomeObj: (value: Partial<SomeObj>) => SomeObj;
+  readonly getPartialPartial: (
     value1: Partial<SomeObj>,
     value2: PartialSomeObj,
   ) => SomeObj;
diff --git a/packages/react-native-codegen/e2e/deep_imports/__test_fixtures__/modules/NativePromiseTurboModule.js b/packages/react-native-codegen/e2e/deep_imports/__test_fixtures__/modules/NativePromiseTurboModule.js
index 689eccb5cf51..9eaeb0f2f823 100644
--- a/packages/react-native-codegen/e2e/deep_imports/__test_fixtures__/modules/NativePromiseTurboModule.js
+++ b/packages/react-native-codegen/e2e/deep_imports/__test_fixtures__/modules/NativePromiseTurboModule.js
@@ -16,8 +16,8 @@ export type String = string;
 type AnotherPromise = Promise<String>;
 
 export interface Spec extends TurboModule {
-  +getValueWithPromise: (error: boolean) => Promise<string>;
-  +getValueWithPromiseWithAlias: (arg: String) => AnotherPromise;
+  readonly getValueWithPromise: (error: boolean) => Promise<string>;
+  readonly getValueWithPromiseWithAlias: (arg: String) => AnotherPromise;
 }
 
 export default TurboModuleRegistry.getEnforcing<Spec>(
diff --git a/packages/react-native-codegen/e2e/deep_imports/__test_fixtures__/modules/NativeSampleTurboModule.js b/packages/react-native-codegen/e2e/deep_imports/__test_fixtures__/modules/NativeSampleTurboModule.js
index 958993293524..a1f7c0b1fd78 100644
--- a/packages/react-native-codegen/e2e/deep_imports/__test_fixtures__/modules/NativeSampleTurboModule.js
+++ b/packages/react-native-codegen/e2e/deep_imports/__test_fixtures__/modules/NativeSampleTurboModule.js
@@ -21,23 +21,23 @@ type Animal = {
 
 export interface Spec extends TurboModule {
   // Exported methods.
-  +getConstants: () => {
+  readonly getConstants: () => {
     const1: boolean,
     const2: number,
     const3: string,
   };
-  +voidFunc: () => void;
-  +getBool: (arg: boolean) => boolean;
-  +getNumber: (arg: number) => number;
-  +getString: (arg: string) => string;
-  +getArray: (arg: Array<any>) => Array<any>;
-  +getObject: (arg: Object) => Object;
-  +getObjectShape: (arg: {prop: number}) => {prop: number};
-  +getAlias: (arg: Animal) => Animal;
-  +getRootTag: (arg: RootTag) => RootTag;
-  +getValue: (x: number, y: string, z: Object) => Object;
-  +getValueWithCallback: (callback: (value: string) => void) => void;
-  +getValueWithPromise: (error: boolean) => Promise<string>;
+  readonly voidFunc: () => void;
+  readonly getBool: (arg: boolean) => boolean;
+  readonly getNumber: (arg: number) => number;
+  readonly getString: (arg: string) => string;
+  readonly getArray: (arg: Array<any>) => Array<any>;
+  readonly getObject: (arg: Object) => Object;
+  readonly getObjectShape: (arg: {prop: number}) => {prop: number};
+  readonly getAlias: (arg: Animal) => Animal;
+  readonly getRootTag: (arg: RootTag) => RootTag;
+  readonly getValue: (x: number, y: string, z: Object) => Object;
+  readonly getValueWithCallback: (callback: (value: string) => void) => void;
+  readonly getValueWithPromise: (error: boolean) => Promise<string>;
 }
 
 export default TurboModuleRegistry.getEnforcing<Spec>(
diff --git a/packages/react-native-codegen/e2e/deep_imports/__test_fixtures__/modules/NativeSampleTurboModuleArrays.js b/packages/react-native-codegen/e2e/deep_imports/__test_fixtures__/modules/NativeSampleTurboModuleArrays.js
index b187b5c0e38f..790a5a4861e3 100644
--- a/packages/react-native-codegen/e2e/deep_imports/__test_fixtures__/modules/NativeSampleTurboModuleArrays.js
+++ b/packages/react-native-codegen/e2e/deep_imports/__test_fixtures__/modules/NativeSampleTurboModuleArrays.js
@@ -21,28 +21,34 @@ type Animal = {
 
 export interface Spec extends TurboModule {
   // Exported methods.
-  +getConstants: () => {
+  readonly getConstants: () => {
     const1: Array<boolean>,
     const2: Array<number>,
     const3: Array<string>,
     id?: Array<?{prop: number}>,
   };
-  +voidFunc: () => void;
-  +getBool: (id: Array<boolean>) => Array<boolean>;
-  +getNumber: (arg: Array<number>) => Array<number>;
-  +getString: (arg: Array<string>) => Array<string>;
-  +getArray: (arg: Array<Array<any>>) => Array<Array<any>>;
-  +getObject: (arg: Array<Object>) => Array<Object>;
-  +getObjectShape: (arg: Array<{prop: number}>) => Array<{prop: number}>;
-  +getAlias: (arg: Array<Animal>) => Array<Animal>;
-  +getRootTag: (arg: Array<RootTag>) => Array<RootTag>;
-  +getValue: (
+  readonly voidFunc: () => void;
+  readonly getBool: (id: Array<boolean>) => Array<boolean>;
+  readonly getNumber: (arg: Array<number>) => Array<number>;
+  readonly getString: (arg: Array<string>) => Array<string>;
+  readonly getArray: (arg: Array<Array<any>>) => Array<Array<any>>;
+  readonly getObject: (arg: Array<Object>) => Array<Object>;
+  readonly getObjectShape: (
+    arg: Array<{prop: number}>,
+  ) => Array<{prop: number}>;
+  readonly getAlias: (arg: Array<Animal>) => Array<Animal>;
+  readonly getRootTag: (arg: Array<RootTag>) => Array<RootTag>;
+  readonly getValue: (
     x: Array<number>,
     y: Array<string>,
     z: Array<Object>,
   ) => Array<Object>;
-  +getValueWithCallback: (callback: (value: Array<string>) => void) => void;
-  +getValueWithPromise: (error: Array<boolean>) => Promise<Array<string>>;
+  readonly getValueWithCallback: (
+    callback: (value: Array<string>) => void,
+  ) => void;
+  readonly getValueWithPromise: (
+    error: Array<boolean>,
+  ) => Promise<Array<string>>;
 }
 
 export default TurboModuleRegistry.getEnforcing<Spec>(
diff --git a/packages/react-native-codegen/e2e/deep_imports/__test_fixtures__/modules/NativeSampleTurboModuleNullable.js b/packages/react-native-codegen/e2e/deep_imports/__test_fixtures__/modules/NativeSampleTurboModuleNullable.js
index a004705148a2..d635d0d23e63 100644
--- a/packages/react-native-codegen/e2e/deep_imports/__test_fixtures__/modules/NativeSampleTurboModuleNullable.js
+++ b/packages/react-native-codegen/e2e/deep_imports/__test_fixtures__/modules/NativeSampleTurboModuleNullable.js
@@ -21,23 +21,23 @@ type Animal = ?{
 
 export interface Spec extends TurboModule {
   // Exported methods.
-  +getConstants: () => {
+  readonly getConstants: () => {
     const1: ?boolean,
     const2: ?number,
     const3: ?string,
   };
-  +voidFunc: () => void;
-  +getBool: (arg: ?boolean) => ?boolean;
-  +getNumber: (arg: ?number) => ?number;
-  +getString: (arg: ?string) => ?string;
-  +getArray: (arg: ?Array<any>) => ?Array<any>;
-  +getObject: (arg: ?Object) => ?Object;
-  +getObjectShape: (arg: ?{prop: ?number}) => ?{prop: ?number};
-  +getAlias: (arg: ?Animal) => ?Animal;
-  +getRootTag: (arg: ?RootTag) => ?RootTag;
-  +getValue: (x: ?number, y: ?string, z: ?Object) => ?Object;
-  +getValueWithCallback: (callback: (value: ?string) => void) => void;
-  +getValueWithPromise: (error: ?boolean) => ?Promise<string>;
+  readonly voidFunc: () => void;
+  readonly getBool: (arg: ?boolean) => ?boolean;
+  readonly getNumber: (arg: ?number) => ?number;
+  readonly getString: (arg: ?string) => ?string;
+  readonly getArray: (arg: ?Array<any>) => ?Array<any>;
+  readonly getObject: (arg: ?Object) => ?Object;
+  readonly getObjectShape: (arg: ?{prop: ?number}) => ?{prop: ?number};
+  readonly getAlias: (arg: ?Animal) => ?Animal;
+  readonly getRootTag: (arg: ?RootTag) => ?RootTag;
+  readonly getValue: (x: ?number, y: ?string, z: ?Object) => ?Object;
+  readonly getValueWithCallback: (callback: (value: ?string) => void) => void;
+  readonly getValueWithPromise: (error: ?boolean) => ?Promise<string>;
 }
 
 export default TurboModuleRegistry.getEnforcing<Spec>(
diff --git a/packages/react-native-codegen/e2e/deep_imports/__test_fixtures__/modules/NativeSampleTurboModuleNullableAndOptional.js b/packages/react-native-codegen/e2e/deep_imports/__test_fixtures__/modules/NativeSampleTurboModuleNullableAndOptional.js
index c5ce3699a5bc..b9fb069bca05 100644
--- a/packages/react-native-codegen/e2e/deep_imports/__test_fixtures__/modules/NativeSampleTurboModuleNullableAndOptional.js
+++ b/packages/react-native-codegen/e2e/deep_imports/__test_fixtures__/modules/NativeSampleTurboModuleNullableAndOptional.js
@@ -21,23 +21,25 @@ type Animal = ?{
 
 export interface Spec extends TurboModule {
   // Exported methods.
-  +getConstants?: () => {
+  readonly getConstants?: () => {
     const1?: ?boolean,
     const2?: ?number,
     const3?: ?string,
   };
-  +voidFunc?: () => void;
-  +getBool?: (arg?: ?boolean) => ?boolean;
-  +getNumber?: (arg?: ?number) => ?number;
-  +getString?: (arg?: ?string) => ?string;
-  +getArray?: (arg?: ?Array<any>) => ?Array<any>;
-  +getObject?: (arg?: ?Object) => ?Object;
-  +getObjectShape?: (arg?: {prop?: ?number}) => {prop?: ?number};
-  +getAlias?: (arg?: ?Animal) => ?Animal;
-  +getRootTag?: (arg?: ?RootTag) => ?RootTag;
-  +getValue?: (x?: ?number, y?: ?string, z?: ?Object) => ?Object;
-  +getValueWithCallback?: (callback?: ?(value?: ?string) => void) => void;
-  +getValueWithPromise?: (error?: ?boolean) => ?Promise<string>;
+  readonly voidFunc?: () => void;
+  readonly getBool?: (arg?: ?boolean) => ?boolean;
+  readonly getNumber?: (arg?: ?number) => ?number;
+  readonly getString?: (arg?: ?string) => ?string;
+  readonly getArray?: (arg?: ?Array<any>) => ?Array<any>;
+  readonly getObject?: (arg?: ?Object) => ?Object;
+  readonly getObjectShape?: (arg?: {prop?: ?number}) => {prop?: ?number};
+  readonly getAlias?: (arg?: ?Animal) => ?Animal;
+  readonly getRootTag?: (arg?: ?RootTag) => ?RootTag;
+  readonly getValue?: (x?: ?number, y?: ?string, z?: ?Object) => ?Object;
+  readonly getValueWithCallback?: (
+    callback?: ?(value?: ?string) => void,
+  ) => void;
+  readonly getValueWithPromise?: (error?: ?boolean) => ?Promise<string>;
 }
 
 export default TurboModuleRegistry.getEnforcing<Spec>(
diff --git a/packages/react-native-codegen/e2e/deep_imports/__test_fixtures__/modules/NativeSampleTurboModuleOptional.js b/packages/react-native-codegen/e2e/deep_imports/__test_fixtures__/modules/NativeSampleTurboModuleOptional.js
index 8e070fe6ce34..c5aa1d50eb81 100644
--- a/packages/react-native-codegen/e2e/deep_imports/__test_fixtures__/modules/NativeSampleTurboModuleOptional.js
+++ b/packages/react-native-codegen/e2e/deep_imports/__test_fixtures__/modules/NativeSampleTurboModuleOptional.js
@@ -21,23 +21,23 @@ type Animal = {
 
 export interface Spec extends TurboModule {
   // Exported methods.
-  +getConstants?: () => {
+  readonly getConstants?: () => {
     const1?: boolean,
     const2?: number,
     const3?: string,
   };
-  +voidFunc?: () => void;
-  +getBool?: (arg?: boolean) => boolean;
-  +getNumber?: (arg?: number) => number;
-  +getString?: (arg?: string) => string;
-  +getArray?: (arg?: Array<any>) => Array<any>;
-  +getObject?: (arg?: Object) => Object;
-  +getObjectShape?: (arg?: {prop?: number}) => {prop?: number};
-  +getAlias?: (arg?: Animal) => Animal;
-  +getRootTag?: (arg?: RootTag) => RootTag;
-  +getValue?: (x?: number, y?: string, z?: Object) => Object;
-  +getValueWithCallback?: (callback?: (value?: string) => void) => void;
-  +getValueWithPromise?: (error?: boolean) => Promise<string>;
+  readonly voidFunc?: () => void;
+  readonly getBool?: (arg?: boolean) => boolean;
+  readonly getNumber?: (arg?: number) => number;
+  readonly getString?: (arg?: string) => string;
+  readonly getArray?: (arg?: Array<any>) => Array<any>;
+  readonly getObject?: (arg?: Object) => Object;
+  readonly getObjectShape?: (arg?: {prop?: number}) => {prop?: number};
+  readonly getAlias?: (arg?: Animal) => Animal;
+  readonly getRootTag?: (arg?: RootTag) => RootTag;
+  readonly getValue?: (x?: number, y?: string, z?: Object) => Object;
+  readonly getValueWithCallback?: (callback?: (value?: string) => void) => void;
+  readonly getValueWithPromise?: (error?: boolean) => Promise<string>;
 }
 
 export default TurboModuleRegistry.getEnforcing<Spec>(
diff --git a/packages/react-native-codegen/e2e/deep_imports/__test_fixtures__/modules/NativeStringTurboModule.js b/packages/react-native-codegen/e2e/deep_imports/__test_fixtures__/modules/NativeStringTurboModule.js
index 76b1964cae54..2ae70cf5a62d 100644
--- a/packages/react-native-codegen/e2e/deep_imports/__test_fixtures__/modules/NativeStringTurboModule.js
+++ b/packages/react-native-codegen/e2e/deep_imports/__test_fixtures__/modules/NativeStringTurboModule.js
@@ -16,8 +16,8 @@ export type String = string;
 type AnotherString = String;
 
 export interface Spec extends TurboModule {
-  +getString: (arg: string) => string;
-  +getStringWithAlias: (arg: String) => AnotherString;
+  readonly getString: (arg: string) => string;
+  readonly getStringWithAlias: (arg: String) => AnotherString;
 }
 
 export default TurboModuleRegistry.getEnforcing<Spec>(
diff --git a/packages/react-native/Libraries/Animated/createAnimatedComponent.js b/packages/react-native/Libraries/Animated/createAnimatedComponent.js
index 435aea045ce6..b6b3953b429d 100644
--- a/packages/react-native/Libraries/Animated/createAnimatedComponent.js
+++ b/packages/react-native/Libraries/Animated/createAnimatedComponent.js
@@ -51,7 +51,7 @@ export type WithAnimatedValue<out T> = T extends Builtin | Nullable
     : T extends ReadonlyArray<infer P>
       ? ReadonlyArray<WithAnimatedValue<P>>
       : T extends {...}
-        ? {+[K in keyof T]: WithAnimatedValue<T[K]>}
+        ? {readonly [K in keyof T]: WithAnimatedValue<T[K]>}
         : T;
 
 type NonAnimatedProps =
diff --git a/packages/react-native/scripts/ios-prebuild/hermes.js b/packages/react-native/scripts/ios-prebuild/hermes.js
index 94f7883b49b1..eb3df6314352 100644
--- a/packages/react-native/scripts/ios-prebuild/hermes.js
+++ b/packages/react-native/scripts/ios-prebuild/hermes.js
@@ -133,8 +133,8 @@ type HermesEngineSourceType =
 */
 
 const HermesEngineSourceTypes /*:{
-  +DOWNLOAD_PREBUILD_TARBALL: "download_prebuild_tarball",
-  +LOCAL_PREBUILT_TARBALL: "local_prebuilt_tarball"
+  readonly DOWNLOAD_PREBUILD_TARBALL: "download_prebuild_tarball",
+  readonly LOCAL_PREBUILT_TARBALL: "local_prebuilt_tarball"
 } */ = {
   LOCAL_PREBUILT_TARBALL: 'local_prebuilt_tarball',
   DOWNLOAD_PREBUILD_TARBALL: 'download_prebuild_tarball',
diff --git a/packages/react-native/scripts/ios-prebuild/reactNativeDependencies.js b/packages/react-native/scripts/ios-prebuild/reactNativeDependencies.js
index 7bd799d83b8e..f497338bef8b 100644
--- a/packages/react-native/scripts/ios-prebuild/reactNativeDependencies.js
+++ b/packages/react-native/scripts/ios-prebuild/reactNativeDependencies.js
@@ -124,8 +124,8 @@ type ReactNativeDependenciesEngineSourceType =
 */
 
 const ReactNativeDependenciesEngineSourceTypes /*: {
-  +DOWNLOAD_PREBUILD_TARBALL: "download_prebuild_tarball",
-  +DOWNLOAD_PREBUILT_NIGHTLY_TARBALL: "download_prebuilt_nightly_tarball"
+  readonly DOWNLOAD_PREBUILD_TARBALL: "download_prebuild_tarball",
+  readonly DOWNLOAD_PREBUILT_NIGHTLY_TARBALL: "download_prebuilt_nightly_tarball"
 } */ = {
   DOWNLOAD_PREBUILD_TARBALL: 'download_prebuild_tarball',
   DOWNLOAD_PREBUILT_NIGHTLY_TARBALL: 'download_prebuilt_nightly_tarball',
diff --git a/private/core-cli-utils/src/private/app.js b/private/core-cli-utils/src/private/app.js
index afb792541432..21e9ea297dcc 100644
--- a/private/core-cli-utils/src/private/app.js
+++ b/private/core-cli-utils/src/private/app.js
@@ -27,7 +27,7 @@ type BundlerOptions = {
   config?: string,
   // Typically index.{ios,android}.js
   entryFile: string,
-  +platform: 'ios' | 'android' | string,
+  readonly platform: 'ios' | 'android' | string,
   dev: boolean,
   // Metro built main bundle
   outputJsBundle: string,
@@ -58,12 +58,12 @@ type HermesConfig = {
 };
 
 type BundlerWatch = {
-  +mode: 'watch',
+  readonly mode: 'watch',
   callback?: (metro: ExecaPromise) => void,
 };
 
 type BundlerBuild = {
-  +mode: 'bundle',
+  readonly mode: 'bundle',
 };
 
 type Bundler = BundlerWatch | BundlerBuild;