diff --git a/services/core/java/com/android/server/wm/WindowState.java b/services/core/java/com/android/server/wm/WindowState.java
index 4ad021e1c00c8..617d2b4d28e3a 100644
--- a/services/core/java/com/android/server/wm/WindowState.java
+++ b/services/core/java/com/android/server/wm/WindowState.java
@@ -101,6 +101,10 @@ import static com.android.server.wm.WindowManagerDebugConfig.TAG_WITH_CLASS_NAME
 import static com.android.server.wm.WindowManagerDebugConfig.TAG_WM;
 
 class WindowList extends ArrayList<WindowState> {
+    WindowList() {}
+    WindowList(WindowList windowList) {
+        super(windowList);
+    }
 }
 
 /**
diff --git a/services/core/java/com/android/server/wm/WindowStateAnimator.java b/services/core/java/com/android/server/wm/WindowStateAnimator.java
index c1ff96e72ae57..bf8a62e5787de 100644
--- a/services/core/java/com/android/server/wm/WindowStateAnimator.java
+++ b/services/core/java/com/android/server/wm/WindowStateAnimator.java
@@ -434,9 +434,12 @@ class WindowStateAnimator {
                 + " remove=" + mWin.mRemoveOnExit
                 + " windowAnimating=" + isWindowAnimating());
 
-        final int N = mWin.mChildWindows.size();
-        for (int i=0; i<N; i++) {
-            mWin.mChildWindows.get(i).mWinAnimator.finishExit();
+        if (!mWin.mChildWindows.isEmpty()) {
+            // Copying to a different list as multiple children can be removed.
+            final WindowList childWindows = new WindowList(mWin.mChildWindows);
+            for (int i = childWindows.size() - 1; i >= 0; i--) {
+                childWindows.get(i).mWinAnimator.finishExit();
+            }
         }
 
         if (mEnteringAnimation) {