diff --git a/Libraries/FBReactNativeSpec/FBReactNativeSpec/FBReactNativeSpec.h b/Libraries/FBReactNativeSpec/FBReactNativeSpec/FBReactNativeSpec.h
index bb1c8d2d99a67f..4e361e2bef43d4 100644
--- a/Libraries/FBReactNativeSpec/FBReactNativeSpec/FBReactNativeSpec.h
+++ b/Libraries/FBReactNativeSpec/FBReactNativeSpec/FBReactNativeSpec.h
@@ -1682,7 +1682,7 @@ namespace JS {
 }
 @protocol NativeJSDevSupportSpec <RCTBridgeModule, RCTTurboModule>
 
-- (void)onSuccess:(NSDictionary *)data;
+- (void)onSuccess:(NSString *)data;
 - (void)onFailure:(double)errorCode
             error:(NSString *)error;
 - (facebook::react::ModuleConstants<JS::NativeJSDevSupport::Constants::Builder>)constantsToExport;
diff --git a/Libraries/Utilities/NativeJSDevSupport.js b/Libraries/Utilities/NativeJSDevSupport.js
index 3128d3d83bd214..0c140f0f9621f3 100644
--- a/Libraries/Utilities/NativeJSDevSupport.js
+++ b/Libraries/Utilities/NativeJSDevSupport.js
@@ -18,7 +18,7 @@ export interface Spec extends TurboModule {
     ERROR_CODE_EXCEPTION: number,
     ERROR_CODE_VIEW_NOT_FOUND: number,
   |};
-  +onSuccess: (data: Object) => void;
+  +onSuccess: (data: string) => void;
   +onFailure: (errorCode: number, error: string) => void;
 }
 
diff --git a/ReactAndroid/src/main/java/com/facebook/fbreact/specs/NativeJSDevSupportSpec.java b/ReactAndroid/src/main/java/com/facebook/fbreact/specs/NativeJSDevSupportSpec.java
index 4663777a6c2f40..4e76f968ae6923 100644
--- a/ReactAndroid/src/main/java/com/facebook/fbreact/specs/NativeJSDevSupportSpec.java
+++ b/ReactAndroid/src/main/java/com/facebook/fbreact/specs/NativeJSDevSupportSpec.java
@@ -16,7 +16,6 @@
 import com.facebook.react.bridge.ReactContextBaseJavaModule;
 import com.facebook.react.bridge.ReactMethod;
 import com.facebook.react.bridge.ReactModuleWithSpec;
-import com.facebook.react.bridge.ReadableMap;
 import com.facebook.react.common.build.ReactBuildConfig;
 import com.facebook.react.turbomodule.core.interfaces.TurboModule;
 import java.util.Arrays;
@@ -34,7 +33,7 @@ public NativeJSDevSupportSpec(ReactApplicationContext reactContext) {
   public abstract void onFailure(double errorCode, String error);
 
   @ReactMethod
-  public abstract void onSuccess(ReadableMap data);
+  public abstract void onSuccess(String data);
 
   protected abstract Map<String, Object> getTypedExportedConstants();