diff --git a/Tethering/common/TetheringLib/src/android/net/TetheringManager.java b/Tethering/common/TetheringLib/src/android/net/TetheringManager.java
index 2963f87..e69f2dd 100644
--- a/Tethering/common/TetheringLib/src/android/net/TetheringManager.java
+++ b/Tethering/common/TetheringLib/src/android/net/TetheringManager.java
@@ -1353,6 +1353,9 @@
     @RequiresPermission(Manifest.permission.ACCESS_NETWORK_STATE)
     public void registerTetheringEventCallback(@NonNull Executor executor,
             @NonNull TetheringEventCallback callback) {
+        Objects.requireNonNull(executor);
+        Objects.requireNonNull(callback);
+
         final String callerPkg = mContext.getOpPackageName();
         Log.i(TAG, "registerTetheringEventCallback caller:" + callerPkg);
 
@@ -1507,6 +1510,8 @@
             Manifest.permission.ACCESS_NETWORK_STATE
     })
     public void unregisterTetheringEventCallback(@NonNull final TetheringEventCallback callback) {
+        Objects.requireNonNull(callback);
+
         final String callerPkg = mContext.getOpPackageName();
         Log.i(TAG, "unregisterTetheringEventCallback caller:" + callerPkg);
 
diff --git a/Tethering/src/com/android/networkstack/tethering/Tethering.java b/Tethering/src/com/android/networkstack/tethering/Tethering.java
index 0ff89d3..4631262 100644
--- a/Tethering/src/com/android/networkstack/tethering/Tethering.java
+++ b/Tethering/src/com/android/networkstack/tethering/Tethering.java
@@ -2400,9 +2400,6 @@
                 hasCallingPermission(NETWORK_SETTINGS)
                         || hasCallingPermission(PERMISSION_MAINLINE_NETWORK_STACK)
                         || hasCallingPermission(NETWORK_STACK);
-        if (callback == null) {
-            throw new NullPointerException();
-        }
         mHandler.post(() -> {
             mTetheringEventCallbacks.register(callback, new CallbackCookie(hasListPermission));
             final TetheringCallbackStartedParcel parcel = new TetheringCallbackStartedParcel();
@@ -2440,9 +2437,6 @@
 
     /** Unregister tethering event callback */
     void unregisterTetheringEventCallback(ITetheringEventCallback callback) {
-        if (callback == null) {
-            throw new NullPointerException();
-        }
         mHandler.post(() -> {
             mTetheringEventCallbacks.unregister(callback);
         });
diff --git a/Tethering/src/com/android/networkstack/tethering/TetheringService.java b/Tethering/src/com/android/networkstack/tethering/TetheringService.java
index 623f502..93b3508 100644
--- a/Tethering/src/com/android/networkstack/tethering/TetheringService.java
+++ b/Tethering/src/com/android/networkstack/tethering/TetheringService.java
@@ -163,6 +163,8 @@
         @Override
         public void registerTetheringEventCallback(ITetheringEventCallback callback,
                 String callerPkg) {
+            // Silently ignore call if the callback is null. This can only happen via reflection.
+            if (callback == null) return;
             try {
                 if (!hasTetherAccessPermission()) {
                     callback.onCallbackStopped(TETHER_ERROR_NO_ACCESS_TETHERING_PERMISSION);
@@ -175,6 +177,8 @@
         @Override
         public void unregisterTetheringEventCallback(ITetheringEventCallback callback,
                 String callerPkg) {
+            // Silently ignore call if the callback is null. This can only happen via reflection.
+            if (callback == null) return;
             try {
                 if (!hasTetherAccessPermission()) {
                     callback.onCallbackStopped(TETHER_ERROR_NO_ACCESS_TETHERING_PERMISSION);