diff --git a/js/ui/workspaceThumbnail.js b/js/ui/workspaceThumbnail.js
index c5cd7e360..d8532806e 100644
--- a/js/ui/workspaceThumbnail.js
+++ b/js/ui/workspaceThumbnail.js
@@ -739,6 +739,10 @@ const ThumbnailsBox = new Lang.Class({
 
             // Nab all the windows below us.
             let windows = global.get_window_actors().filter(function(win) {
+                // If the window is attached to an ancestor, we don't need/want to move it
+                if (!!win.meta_window.get_transient_for())
+                    return false;
+                
                 if (isWindow)
                     return win.get_workspace() >= newWorkspaceIndex && win != source;
                 else