diff --git a/packages/remote-config/lib/index.d.ts b/packages/remote-config/lib/index.d.ts
index eb93d0fb9a..bb48d647b0 100644
--- a/packages/remote-config/lib/index.d.ts
+++ b/packages/remote-config/lib/index.d.ts
@@ -540,6 +540,17 @@ export namespace FirebaseRemoteConfigTypes {
      */
     reset(): Promise<void>;
   }
+
+  export type CallbackOrObserver<T extends (...args: any[]) => any> = T | { next: T };
+
+  export type OnConfigUpdatedListenerCallback = (
+    event?: { updatedKeys: string[] },
+    error?: {
+      code: string;
+      message: string;
+      nativeErrorMessage: string;
+    },
+  ) => void;
 }
 
 declare const defaultExport: ReactNativeFirebase.FirebaseModuleWithStatics<
@@ -554,17 +565,6 @@ export const firebase: ReactNativeFirebase.Module & {
   ): ReactNativeFirebase.FirebaseApp & { remoteConfig(): FirebaseRemoteConfigTypes.Module };
 };
 
-type CallbackOrObserver<T extends (...args: any[]) => any> = T | { next: T };
-
-type OnConfigUpdatedListenerCallback = (
-  event?: { updatedKeys: string[] },
-  error?: {
-    code: string;
-    message: string;
-    nativeErrorMessage: string;
-  },
-) => void;
-
 export default defaultExport;
 
 export * from './modular';
diff --git a/packages/remote-config/lib/modular/index.d.ts b/packages/remote-config/lib/modular/index.d.ts
index 768ffc616b..062cc01d82 100644
--- a/packages/remote-config/lib/modular/index.d.ts
+++ b/packages/remote-config/lib/modular/index.d.ts
@@ -27,6 +27,8 @@ import RemoteConfigLogLevel = FirebaseRemoteConfigTypes.RemoteConfigLogLevel;
 import FirebaseApp = ReactNativeFirebase.FirebaseApp;
 import LastFetchStatusInterface = FirebaseRemoteConfigTypes.LastFetchStatus;
 import ValueSourceInterface = FirebaseRemoteConfigTypes.ValueSource;
+import CallbackOrObserver = FirebaseRemoteConfigTypes.CallbackOrObserver;
+import OnConfigUpdatedListenerCallback = FirebaseRemoteConfigTypes.OnConfigUpdatedListenerCallback;
 
 export const LastFetchStatus: LastFetchStatusInterface;
 export const ValueSource: ValueSourceInterface;
@@ -210,7 +212,7 @@ export function setDefaultsFromResource(
  */
 export function onConfigUpdated(
   remoteConfig: RemoteConfig,
-  callback: (config: ConfigValues) => void,
+  callback: CallbackOrObserver<OnConfigUpdatedListenerCallback>,
 ): () => void;
 
 /**
diff --git a/packages/remote-config/lib/modular/index.js b/packages/remote-config/lib/modular/index.js
index a217116486..569cf49e08 100644
--- a/packages/remote-config/lib/modular/index.js
+++ b/packages/remote-config/lib/modular/index.js
@@ -243,7 +243,7 @@ export function setDefaultsFromResource(remoteConfig, resourceName) {
  * Registers a listener to changes in the configuration.
  *
  * @param {RemoteConfig} remoteConfig - RemoteConfig instance
- * @param {function(ConfigValues): void} callback - function called on config change
+ * @param {CallbackOrObserver<OnConfigUpdatedListenerCallback>} callback - function called on config change
  * @returns {function} unsubscribe listener
  */
 export function onConfigUpdated(remoteConfig, callback) {