diff --git a/js/ui/workspace.js b/js/ui/workspace.js
index 3a07585ad..2d487660e 100644
--- a/js/ui/workspace.js
+++ b/js/ui/workspace.js
@@ -1113,7 +1113,9 @@ Workspace.prototype = {
             // the compositor finds out about them...
             Mainloop.idle_add(Lang.bind(this,
                                         function () {
-                                            if (this.actor && metaWin.get_compositor_private())
+                                            if (this.actor &&
+                                                metaWin.get_compositor_private() &&
+                                                metaWin.get_workspace() == this.metaWorkspace)
                                                 this._doAddWindow(metaWin);
                                             return false;
                                         }));
diff --git a/js/ui/workspaceThumbnail.js b/js/ui/workspaceThumbnail.js
index 96fd52bc5..8c12e86c0 100644
--- a/js/ui/workspaceThumbnail.js
+++ b/js/ui/workspaceThumbnail.js
@@ -276,7 +276,9 @@ WorkspaceThumbnail.prototype = {
             // the compositor finds out about them...
             Mainloop.idle_add(Lang.bind(this,
                                         function () {
-                                            if (this.actor && metaWin.get_compositor_private())
+                                            if (this.actor &&
+                                                metaWin.get_compositor_private() &&
+                                                metaWin.get_workspace() == this.metaWorkspace)
                                                 this._doAddWindow(metaWin);
                                             return false;
                                         }));