diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/splitscreen/StageTaskListener.java b/libs/WindowManager/Shell/src/com/android/wm/shell/splitscreen/StageTaskListener.java
index f438f912a51bc..23eec96a5d8f4 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/splitscreen/StageTaskListener.java
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/splitscreen/StageTaskListener.java
@@ -26,6 +26,7 @@ import static android.app.WindowConfiguration.WINDOWING_MODE_UNDEFINED;
 import static com.android.wm.shell.transition.Transitions.ENABLE_SHELL_TRANSITIONS;
 
 import android.annotation.CallSuper;
+import android.annotation.Nullable;
 import android.app.ActivityManager;
 import android.content.Context;
 import android.graphics.Point;