diff --git a/core/java/android/service/autofill/IFillCallback.aidl b/core/java/android/service/autofill/IFillCallback.aidl
index 1bad1d7f474a5..32cf712b5fd41 100644
--- a/core/java/android/service/autofill/IFillCallback.aidl
+++ b/core/java/android/service/autofill/IFillCallback.aidl
@@ -25,7 +25,7 @@ import android.service.autofill.FillResponse;
  *
  * @hide
  */
-interface IFillCallback {
+oneway interface IFillCallback {
     void onCancellable(in ICancellationSignal cancellation);
     void onSuccess(in FillResponse response);
     void onFailure(int requestId, CharSequence message);