diff --git a/vibrator/aidl/aidl_api/android.hardware.vibrator/current/android/hardware/vibrator/CompositeEffect.aidl b/vibrator/aidl/aidl_api/android.hardware.vibrator/current/android/hardware/vibrator/CompositeEffect.aidl
index 8cb259f..7431804 100644
--- a/vibrator/aidl/aidl_api/android.hardware.vibrator/current/android/hardware/vibrator/CompositeEffect.aidl
+++ b/vibrator/aidl/aidl_api/android.hardware.vibrator/current/android/hardware/vibrator/CompositeEffect.aidl
@@ -19,6 +19,6 @@
 @VintfStability
 parcelable CompositeEffect {
   int delayMs;
-  android.hardware.vibrator.CompositePrimitive primitive;
+  android.hardware.vibrator.CompositePrimitive primitive = android.hardware.vibrator.CompositePrimitive.NOOP;
   float scale;
 }
diff --git a/vibrator/aidl/android/hardware/vibrator/CompositeEffect.aidl b/vibrator/aidl/android/hardware/vibrator/CompositeEffect.aidl
index 406a899..5a990c0 100644
--- a/vibrator/aidl/android/hardware/vibrator/CompositeEffect.aidl
+++ b/vibrator/aidl/android/hardware/vibrator/CompositeEffect.aidl
@@ -22,7 +22,7 @@
 parcelable CompositeEffect {
     /* Period of silence preceding primitive. */
     int delayMs;
-    CompositePrimitive primitive;
+    CompositePrimitive primitive = CompositePrimitive.NOOP;
     /*
      * 0.0 (inclusive) - 1.0 (inclusive),
      * where 0.0 is minimum "feelable" amplitude.