diff --git a/services/core/java/com/android/server/wm/WindowContainer.java b/services/core/java/com/android/server/wm/WindowContainer.java
index 33c0fe13af11f..f42df02a62523 100644
--- a/services/core/java/com/android/server/wm/WindowContainer.java
+++ b/services/core/java/com/android/server/wm/WindowContainer.java
@@ -3756,6 +3756,15 @@ class WindowContainer<E extends WindowContainer> extends ConfigurationContainer<
      * hierarchy change implies a configuration change.
      */
     private void onSyncReparent(WindowContainer oldParent, WindowContainer newParent) {
+        // Check if this is changing displays. If so, mark the old display as "ready" for
+        // transitions. This is to work around the problem where setting readiness against this
+        // container will only set the new display as ready and leave the old display as unready.
+        if (mSyncState != SYNC_STATE_NONE && oldParent != null
+                && oldParent.getDisplayContent() != null && (newParent == null
+                        || oldParent.getDisplayContent() != newParent.getDisplayContent())) {
+            mTransitionController.setReady(oldParent.getDisplayContent());
+        }
+
         if (newParent == null || newParent.mSyncState == SYNC_STATE_NONE) {
             if (mSyncState == SYNC_STATE_NONE) {
                 return;