diff --git a/telephony/java/android/telephony/ims/ImsService.java b/telephony/java/android/telephony/ims/ImsService.java
index be233b8..bccb6ef 100644
--- a/telephony/java/android/telephony/ims/ImsService.java
+++ b/telephony/java/android/telephony/ims/ImsService.java
@@ -425,8 +425,8 @@
         }
     }
 
-    private IImsRcsFeature createRcsFeatureInternal(int slotId, int subI) {
-        RcsFeature f = createRcsFeatureForSubscription(slotId, subI);
+    private IImsRcsFeature createRcsFeatureInternal(int slotId, int subId) {
+        RcsFeature f = createRcsFeatureForSubscription(slotId, subId);
         if (f != null) {
             f.setDefaultExecutor(mExecutor);
             setupFeature(f, slotId, ImsFeature.FEATURE_RCS);
diff --git a/telephony/java/android/telephony/ims/feature/ImsFeature.java b/telephony/java/android/telephony/ims/feature/ImsFeature.java
index f5b158f..a42327b 100644
--- a/telephony/java/android/telephony/ims/feature/ImsFeature.java
+++ b/telephony/java/android/telephony/ims/feature/ImsFeature.java
@@ -394,10 +394,12 @@
     @VisibleForTesting
     public void addImsFeatureStatusCallback(@NonNull IImsFeatureStatusCallback c) {
         try {
-            // If we have just connected, send queued status.
-            c.notifyImsFeatureStatus(getFeatureState());
-            // Add the callback if the callback completes successfully without a RemoteException.
-            mStatusCallbacks.register(c);
+            synchronized (mStatusCallbacks) {
+                // Add the callback if the callback completes successfully without a RemoteException
+                mStatusCallbacks.register(c);
+                // If we have just connected, send queued status.
+                c.notifyImsFeatureStatus(getFeatureState());
+            }
         } catch (RemoteException e) {
             Log.w(LOG_TAG, "Couldn't notify feature state: " + e.getMessage());
         }
@@ -409,7 +411,9 @@
      */
     @VisibleForTesting
     public void removeImsFeatureStatusCallback(@NonNull IImsFeatureStatusCallback c) {
-        mStatusCallbacks.unregister(c);
+        synchronized (mStatusCallbacks) {
+            mStatusCallbacks.unregister(c);
+        }
     }
 
     /**