diff --git a/android_webview/browser/aw_field_trials.cc b/android_webview/browser/aw_field_trials.cc
index 0734e3e22b2cba..2460a476bc0106 100644
--- a/android_webview/browser/aw_field_trials.cc
+++ b/android_webview/browser/aw_field_trials.cc
@@ -112,14 +112,6 @@ void AwFieldTrials::RegisterFeatureOverrides(base::FeatureList* feature_list) {
   aw_feature_overrides.DisableFeature(
       net::features::kThirdPartyStoragePartitioning);
 
-  if (!base::FeatureList::IsEnabled(
-          mojo::features::kMojoFixAssociatedHandleLeak)) {
-    // Disable support for partitioning blob URLs if the bug fix that prevents
-    // blob URL creation from hanging under certain conditions isn't enabled.
-    aw_feature_overrides.DisableFeature(
-        net::features::kSupportPartitionedBlobUrl);
-  }
-
   // Disable the passthrough on WebView.
   aw_feature_overrides.DisableFeature(
       ::features::kDefaultPassthroughCommandDecoder);
diff --git a/ipc/ipc_channel_mojo_unittest.cc b/ipc/ipc_channel_mojo_unittest.cc
index 6ac9c774d8b3d2..3137e64f8d6f06 100644
--- a/ipc/ipc_channel_mojo_unittest.cc
+++ b/ipc/ipc_channel_mojo_unittest.cc
@@ -1307,10 +1307,6 @@ TEST_F(IPCChannelProxyMojoTest, DropAssociatedReceiverWithSyncCallInFlight) {
 DEFINE_IPC_CHANNEL_MOJO_TEST_CLIENT_WITH_CUSTOM_FIXTURE(
     SyncCallToDroppedReceiver,
     ChannelProxyClient) {
-  // Force-enable the fix, since ipc_tests doesn't initialize FeatureList.
-  const base::test::ScopedFeatureList kFeatures(
-      mojo::features::kMojoFixAssociatedHandleLeak);
-
   DummyListener listener;
   CreateProxy(&listener);
   RunProxy();
diff --git a/ipc/ipc_mojo_bootstrap.cc b/ipc/ipc_mojo_bootstrap.cc
index 3c608e2185b834..0adaa0f7d8c1ef 100644
--- a/ipc/ipc_mojo_bootstrap.cc
+++ b/ipc/ipc_mojo_bootstrap.cc
@@ -415,11 +415,6 @@ class ChannelAssociatedGroupController
   }
 
   void NotifyLocalEndpointOfPeerClosure(mojo::InterfaceId id) override {
-    if (!base::FeatureList::IsEnabled(
-            mojo::features::kMojoFixAssociatedHandleLeak)) {
-      return;
-    }
-
     if (!task_runner_->RunsTasksInCurrentSequence()) {
       task_runner_->PostTask(
           FROM_HERE, base::BindOnce(&ChannelAssociatedGroupController::
diff --git a/mojo/public/cpp/bindings/features.cc b/mojo/public/cpp/bindings/features.cc
index 3fb9ed90f18e0f..7f2950ba104cfe 100644
--- a/mojo/public/cpp/bindings/features.cc
+++ b/mojo/public/cpp/bindings/features.cc
@@ -41,12 +41,5 @@ BASE_FEATURE(kMojoPredictiveAllocation,
 #endif
 );
 
-// Enables a bugfix for https://crbug.com/331636067. This is a very old bug, and
-// this flag will be used to understand the stability and performance impact of
-// the fix, if any.
-BASE_FEATURE(kMojoFixAssociatedHandleLeak,
-             "MojoFixAssociatedHandleLeak",
-             base::FEATURE_ENABLED_BY_DEFAULT);
-
 }  // namespace features
 }  // namespace mojo
diff --git a/mojo/public/cpp/bindings/features.h b/mojo/public/cpp/bindings/features.h
index c402f740741f75..7ffc8bfc94374b 100644
--- a/mojo/public/cpp/bindings/features.h
+++ b/mojo/public/cpp/bindings/features.h
@@ -19,9 +19,6 @@ BASE_DECLARE_FEATURE(kMojoRecordUnreadMessageCount);
 COMPONENT_EXPORT(MOJO_CPP_BINDINGS_BASE)
 BASE_DECLARE_FEATURE(kMojoPredictiveAllocation);
 
-COMPONENT_EXPORT(MOJO_CPP_BINDINGS_BASE)
-BASE_DECLARE_FEATURE(kMojoFixAssociatedHandleLeak);
-
 }  // namespace features
 }  // namespace mojo
 
diff --git a/mojo/public/cpp/bindings/lib/multiplex_router.cc b/mojo/public/cpp/bindings/lib/multiplex_router.cc
index 8487e80f4ab988..44c75b45ae9cc5 100644
--- a/mojo/public/cpp/bindings/lib/multiplex_router.cc
+++ b/mojo/public/cpp/bindings/lib/multiplex_router.cc
@@ -518,10 +518,6 @@ void MultiplexRouter::CloseEndpointHandle(
 }
 
 void MultiplexRouter::NotifyLocalEndpointOfPeerClosure(InterfaceId id) {
-  if (!base::FeatureList::IsEnabled(features::kMojoFixAssociatedHandleLeak)) {
-    return;
-  }
-
   if (!task_runner_->RunsTasksInCurrentSequence()) {
     task_runner_->PostTask(
         FROM_HERE,
diff --git a/mojo/public/cpp/bindings/tests/associated_interface_unittest.cc b/mojo/public/cpp/bindings/tests/associated_interface_unittest.cc
index 1abbc81d36293c..b9be8b83bc6839 100644
--- a/mojo/public/cpp/bindings/tests/associated_interface_unittest.cc
+++ b/mojo/public/cpp/bindings/tests/associated_interface_unittest.cc
@@ -1195,10 +1195,6 @@ TEST_F(AssociatedInterfaceTest, CloseSerializedAssociatedEndpoints) {
   // lifetime is properly managed when associated endpoints are serialized into
   // a message that gets dropped before transmission.
 
-  // Force-enable the feature since this test requires it to pass.
-  base::test::ScopedFeatureList kFeatures{
-      features::kMojoFixAssociatedHandleLeak};
-
   Remote<mojom::ClumsyBinder> binder;
   ClumsyBinderImpl binder_impl(binder.BindNewPipeAndPassReceiver());