diff --git a/data/theme/gnome-shell.css b/data/theme/gnome-shell.css
index 843ed6cba..bb5d2c468 100644
--- a/data/theme/gnome-shell.css
+++ b/data/theme/gnome-shell.css
@@ -232,6 +232,10 @@ StScrollBar StButton#vhandle:active {
     border-width: 0px;
 }
 
+.app-well-menu {
+    max-width: 400px;
+}
+
 /* The remaining popup-menu sizing is all done in ems, so that if you
  * override .popup-menu.font-size, everything else will scale with it.
  */