diff --git a/src/core/ext/filters/client_channel/subchannel.cc b/src/core/ext/filters/client_channel/subchannel.cc
index 8708cf21c3b..7f15cb416b9 100644
--- a/src/core/ext/filters/client_channel/subchannel.cc
+++ b/src/core/ext/filters/client_channel/subchannel.cc
@@ -202,7 +202,6 @@ class ConnectedSubchannelStateWatcher
   // Must be instantiated while holding c->mu.
   explicit ConnectedSubchannelStateWatcher(grpc_subchannel* c)
       : subchannel_(c) {
-    gpr_mu_init(&mu_);
     // Steal subchannel ref for connecting.
     GRPC_SUBCHANNEL_WEAK_REF(subchannel_, "state_watcher");
     GRPC_SUBCHANNEL_WEAK_UNREF(subchannel_, "connecting");
@@ -235,13 +234,10 @@ class ConnectedSubchannelStateWatcher
 
   ~ConnectedSubchannelStateWatcher() {
     GRPC_SUBCHANNEL_WEAK_UNREF(subchannel_, "state_watcher");
-    gpr_mu_destroy(&mu_);
   }
 
-  void Orphan() override {
-    MutexLock lock(&mu_);
-    health_check_client_.reset();
-  }
+  // Must be called while holding subchannel_->mu.
+  void Orphan() override { health_check_client_.reset(); }
 
  private:
   static void OnConnectivityChanged(void* arg, grpc_error* error) {
@@ -307,13 +303,12 @@ class ConnectedSubchannelStateWatcher
 
   static void OnHealthChanged(void* arg, grpc_error* error) {
     auto* self = static_cast<ConnectedSubchannelStateWatcher*>(arg);
-    MutexLock health_state_lock(&self->mu_);
+    grpc_subchannel* c = self->subchannel_;
+    MutexLock lock(&c->mu);
     if (self->health_state_ == GRPC_CHANNEL_SHUTDOWN) {
       self->Unref();
       return;
     }
-    grpc_subchannel* c = self->subchannel_;
-    MutexLock lock(&c->mu);
     if (self->last_connectivity_state_ == GRPC_CHANNEL_READY) {
       grpc_connectivity_state_set(&c->state_and_health_tracker,
                                   self->health_state_, GRPC_ERROR_REF(error),
@@ -330,8 +325,6 @@ class ConnectedSubchannelStateWatcher
   grpc_core::OrphanablePtr<grpc_core::HealthCheckClient> health_check_client_;
   grpc_closure on_health_changed_;
   grpc_connectivity_state health_state_ = GRPC_CHANNEL_CONNECTING;
-  // Ensure atomic change to health_check_client_ and health_state_.
-  gpr_mu mu_;
 };
 
 }  // namespace grpc_core