diff --git a/service/src/com/android/server/connectivity/CarrierPrivilegeAuthenticator.java b/service/src/com/android/server/connectivity/CarrierPrivilegeAuthenticator.java
index dd1519e..ab7b1a7 100644
--- a/service/src/com/android/server/connectivity/CarrierPrivilegeAuthenticator.java
+++ b/service/src/com/android/server/connectivity/CarrierPrivilegeAuthenticator.java
@@ -119,7 +119,7 @@
             unregisterCarrierPrivilegesListeners();
             mModemCount = mTelephonyManager.getActiveModemCount();
             registerCarrierPrivilegesListeners(mModemCount);
-            updateCarrierServiceUid();
+            if (!mUseCallbacksForServiceChanged) updateCarrierServiceUid();
         }
     }
 
@@ -132,19 +132,26 @@
         @Override public void onCarrierPrivilegesChanged(
                 @NonNull List<String> privilegedPackageNames,
                 @NonNull int[] privilegedUids) {
+            if (mUseCallbacksForServiceChanged) return;
             // Re-trigger the synchronous check (which is also very cheap due
             // to caching in CarrierPrivilegesTracker). This allows consistency
             // with the onSubscriptionsChangedListener and broadcasts.
             updateCarrierServiceUid();
         }
+
         @Override
-        public void onCarrierServiceChanged(
-                @Nullable final String carrierServicePackageName,
+        public void onCarrierServiceChanged(@Nullable final String carrierServicePackageName,
                 final int carrierServiceUid) {
-            // Re-trigger the synchronous check (which is also very cheap due
-            // to caching in CarrierPrivilegesTracker). This allows consistency
-            // with the onSubscriptionsChangedListener and broadcasts.
-            updateCarrierServiceUid();
+            if (!mUseCallbacksForServiceChanged) {
+                // Re-trigger the synchronous check (which is also very cheap due
+                // to caching in CarrierPrivilegesTracker). This allows consistency
+                // with the onSubscriptionsChangedListener and broadcasts.
+                updateCarrierServiceUid();
+                return;
+            }
+            synchronized (mLock) {
+                mCarrierServiceUid.put(mLogicalSlot, carrierServiceUid);
+            }
         }
     }
 
diff --git a/tests/unit/java/com/android/server/connectivity/CarrierPrivilegeAuthenticatorTest.java b/tests/unit/java/com/android/server/connectivity/CarrierPrivilegeAuthenticatorTest.java
index 2ecd2a1..8113626 100644
--- a/tests/unit/java/com/android/server/connectivity/CarrierPrivilegeAuthenticatorTest.java
+++ b/tests/unit/java/com/android/server/connectivity/CarrierPrivilegeAuthenticatorTest.java
@@ -158,6 +158,8 @@
         assertNotNull(initialListeners.get(1));
         assertEquals(2, initialListeners.size());
 
+        initialListeners.get(0).onCarrierServiceChanged(null, mCarrierConfigPkgUid);
+
         final NetworkCapabilities.Builder ncBuilder = new NetworkCapabilities.Builder()
                 .addTransportType(TRANSPORT_CELLULAR)
                 .setNetworkSpecifier(new TelephonyNetworkSpecifier(0));
@@ -194,6 +196,8 @@
         assertNotNull(newListeners.get(0));
         assertEquals(1, newListeners.size());
 
+        newListeners.get(0).onCarrierServiceChanged(null, mCarrierConfigPkgUid);
+
         final TelephonyNetworkSpecifier specifier = new TelephonyNetworkSpecifier(0);
         final NetworkCapabilities nc = new NetworkCapabilities.Builder()
                 .addTransportType(TRANSPORT_CELLULAR)
@@ -219,6 +223,7 @@
         applicationInfo.uid = mCarrierConfigPkgUid + 1;
         doReturn(applicationInfo).when(mPackageManager).getApplicationInfo(eq(mTestPkg), anyInt());
         listener.onCarrierPrivilegesChanged(Collections.emptyList(), new int[] {});
+        listener.onCarrierServiceChanged(null, applicationInfo.uid);
 
         assertFalse(mCarrierPrivilegeAuthenticator.hasCarrierPrivilegeForNetworkCapabilities(
                 mCarrierConfigPkgUid, nc));
@@ -228,6 +233,9 @@
 
     @Test
     public void testDefaultSubscription() throws Exception {
+        final CarrierPrivilegesListenerShim listener = getCarrierPrivilegesListeners().get(0);
+        listener.onCarrierServiceChanged(null, mCarrierConfigPkgUid);
+
         final NetworkCapabilities.Builder ncBuilder = new NetworkCapabilities.Builder();
         ncBuilder.addTransportType(TRANSPORT_CELLULAR);
         assertFalse(mCarrierPrivilegeAuthenticator.hasCarrierPrivilegeForNetworkCapabilities(