diff --git a/ash/quick_pair/fast_pair_handshake/fast_pair_gatt_service_client_impl.cc b/ash/quick_pair/fast_pair_handshake/fast_pair_gatt_service_client_impl.cc
index 15d34c3e36db7c..5199785bd054ec 100644
--- a/ash/quick_pair/fast_pair_handshake/fast_pair_gatt_service_client_impl.cc
+++ b/ash/quick_pair/fast_pair_handshake/fast_pair_gatt_service_client_impl.cc
@@ -524,7 +524,7 @@ void FastPairGattServiceClientImpl::GattDiscoveryCompleteForService(
 
     if (pair_failure.has_value()) {
       NotifyInitializedError(pair_failure.value());
-    } else {
+    } else if (on_initialized_callback_) {
       is_initialized_ = true;
       RecordGattInitializationStep(
           FastPairGattConnectionSteps::kConnectionEstablished);
diff --git a/ash/quick_pair/fast_pair_handshake/fast_pair_gatt_service_client_impl_unittest.cc b/ash/quick_pair/fast_pair_handshake/fast_pair_gatt_service_client_impl_unittest.cc
index 1436d3958a2b89..66750eb7e6b2b6 100644
--- a/ash/quick_pair/fast_pair_handshake/fast_pair_gatt_service_client_impl_unittest.cc
+++ b/ash/quick_pair/fast_pair_handshake/fast_pair_gatt_service_client_impl_unittest.cc
@@ -1291,5 +1291,15 @@ TEST_F(FastPairGattServiceClientTest, WriteEmptyPersonalizedName) {
   WritePersonalizedName(empty);
 }
 
+// Regression test for b/300596153
+TEST_F(FastPairGattServiceClientTest,
+       NoCrashWhenGattDiscoveryCompleteForServiceCalledTwice) {
+  SuccessfulGattConnectionSetUp();
+  NotifyGattDiscoveryCompleteForService(
+      ash::quick_pair::kFastPairBluetoothUuid);
+  NotifyGattDiscoveryCompleteForService(
+      ash::quick_pair::kFastPairBluetoothUuid);
+}
+
 }  // namespace quick_pair
 }  // namespace ash