diff --git a/js/ui/workspace.js b/js/ui/workspace.js
index 112c54e8c..1a230068e 100644
--- a/js/ui/workspace.js
+++ b/js/ui/workspace.js
@@ -1507,7 +1507,7 @@ var Workspace = new Lang.Class({
             if (metaWin.is_attached_dialog()) {
                 let parent = metaWin.get_transient_for();
                 while (parent.is_attached_dialog())
-                    parent = metaWin.get_transient_for();
+                    parent = parent.get_transient_for();
 
                 let idx = this._lookupIndex (parent);
                 if (idx < 0) {
diff --git a/js/ui/workspaceThumbnail.js b/js/ui/workspaceThumbnail.js
index eda5dc38a..4aafcd378 100644
--- a/js/ui/workspaceThumbnail.js
+++ b/js/ui/workspaceThumbnail.js
@@ -416,7 +416,7 @@ var WorkspaceThumbnail = new Lang.Class({
         } else if (metaWin.is_attached_dialog()) {
             let parent = metaWin.get_transient_for();
             while (parent.is_attached_dialog())
-                parent = metaWin.get_transient_for();
+                parent = parent.get_transient_for();
 
             let idx = this._lookupIndex (parent);
             if (idx < 0) {