diff --git a/packages/firebase_remote_config/firebase_remote_config_web/lib/src/interop/firebase_remote_config_interop.dart b/packages/firebase_remote_config/firebase_remote_config_web/lib/src/interop/firebase_remote_config_interop.dart
index 445913d55442..0efb10dc0130 100644
--- a/packages/firebase_remote_config/firebase_remote_config_web/lib/src/interop/firebase_remote_config_interop.dart
+++ b/packages/firebase_remote_config/firebase_remote_config_web/lib/src/interop/firebase_remote_config_interop.dart
@@ -21,7 +21,7 @@ external JSPromise<jsboolean> activate(RemoteConfigJsImpl remoteConfig);
 
 @JS()
 @staticInterop
-external JSPromise ensureInitialized(RemoteConfigJsImpl remoteConfig);
+external JSPromise<jsboolean> ensureInitialized(RemoteConfigJsImpl remoteConfig);
 
 @JS()
 @staticInterop
@@ -29,11 +29,11 @@ external JSPromise<jsboolean> fetchAndActivate(RemoteConfigJsImpl remoteConfig);
 
 @JS()
 @staticInterop
-external JSPromise fetchConfig(RemoteConfigJsImpl remoteConfig);
+external JSPromise<jsboolean> fetchConfig(RemoteConfigJsImpl remoteConfig);
 
 @JS()
 @staticInterop
-external JSAny getAll(RemoteConfigJsImpl remoteConfig);
+external JSObject getAll(RemoteConfigJsImpl remoteConfig);
 
 @JS()
 @staticInterop
@@ -53,7 +53,7 @@ external ValueJsImpl getValue(RemoteConfigJsImpl remoteConfig, JSString key);
 
 @JS()
 @staticInterop
-external JSPromise isSupported();
+external JSPromise<jsboolean> isSupported();
 
 @JS()
 @staticInterop
@@ -66,11 +66,7 @@ external JSPromise setCustomSignals(
 @staticInterop
 external void setLogLevel(RemoteConfigJsImpl remoteConfig, JSString logLevel);
 
-@JS('RemoteConfig')
-@staticInterop
-abstract class RemoteConfigJsImpl {}
-
-extension RemoteConfigJsImplExtension on RemoteConfigJsImpl {
+extension type RemoteConfigJsImpl._(JSObject _) implements JSObject {
 external AppJsImpl get app;
 external SettingsJsImpl get settings;
 external set settings(SettingsJsImpl value);
@@ -80,24 +76,15 @@ extension RemoteConfigJsImplExtension on RemoteConfigJsImpl {
 external JSString get lastFetchStatus;
 }
 
-@JS()
-@staticInterop
-@anonymous
-abstract class ValueJsImpl {}
-
-extension ValueJsImplExtension on ValueJsImpl {
+extension type ValueJsImpl._(JSObject _) implements JSObject {
 external JSBoolean asBoolean();
 external JSNumber asNumber();
 external JSString asString();
 external JSString getSource();
 }
 
-@JS()
-@staticInterop
-@anonymous
-abstract class SettingsJsImpl {}
 
-extension SettingsJsImplExtension on SettingsJsImpl {
+extension type SettingsJsImpl._(JSObject _) implements JSObject {
 external JSNumber get minimumFetchIntervalMillis;
 external set minimumFetchIntervalMillis(JSNumber value);
 external JSNumber get fetchTimeoutMillis;
@@ -121,12 +108,7 @@ extension ConfigUpdateObserverJsImpl on ConfigUpdateObserver {
 external JSAny get complete;
 }
 
-@JS()
-@staticInterop
-@anonymous
-abstract class ConfigUpdateJsImpl {}
-
-extension ConfigUpdateJsImplExtension on ConfigUpdateJsImpl {
+extension type ConfigUpdateJsImpl._(JSObject _) implements JSObject {
 external JSSet getUpdatedKeys();
 }
 
</div><div class="naked_ctrl">
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<p><a href="http://altstyle.alfasado.net">AltStyle</a> によって変換されたページ <a href="https://patch-diff.githubusercontent.com/raw/firebase/flutterfire/pull/17814.diff">(-&gt;オリジナル)</a>
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<option value="contrast">配色反転</option>
<option value="larger-text" selected="selected">文字拡大</option>
<option value="mobile">モバイル</option>
</select>
<input type="submit" value="表示" />
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