--- a/browser/base/content/browser.css
+++ b/browser/base/content/browser.css
@@ -448,17 +448,17 @@ window[chromehidden~="toolbar"] toolbar:
 
 #notification-popup-box[anchorid="geo-notification-icon"] > #geo-notification-icon,
 #notification-popup-box[anchorid="indexedDB-notification-icon"] > #indexedDB-notification-icon,
 #notification-popup-box[anchorid="addons-notification-icon"] > #addons-notification-icon,
 #notification-popup-box[anchorid="password-notification-icon"] > #password-notification-icon {
   display: -moz-box;
 }
 
-#invalid-form-popup {
+#invalid-form-popup > description {
   max-width: 280px;
 }
 
 #geolocation-notification {
   -moz-binding: url("chrome://browser/content/urlbarBindings.xml#geolocation-notification");
 }
 
 /* override hidden="true" for the status bar compatibility shim

--- a/browser/base/content/browser.xul
+++ b/browser/base/content/browser.xul
@@ -164,17 +164,17 @@
 
     <!-- for search and content formfill/pw manager -->
     <panel type="autocomplete" id="PopupAutoComplete" noautofocus="true" hidden="true"/>
 
     <!-- for url bar autocomplete -->
     <panel type="autocomplete-richlistbox" id="PopupAutoCompleteRichResult" noautofocus="true" hidden="true"/>
 
     <!-- for invalid form error message -->
-    <panel id="invalid-form-popup" noautofocus="true" hidden="true" level="parent">
+    <panel id="invalid-form-popup" type="arrow" orient="vertical" noautofocus="true" hidden="true" level="parent">
       <description/>
     </panel>
 
     <panel id="editBookmarkPanel"
            orient="vertical"
            ignorekeys="true"
            hidden="true"
            onpopupshown="StarUI.panelShown(event);"

--- a/browser/themes/gnomestripe/browser/browser.css
+++ b/browser/themes/gnomestripe/browser/browser.css
@@ -1111,17 +1111,16 @@ toolbar[iconsize="small"] #feed-button {
   padding: 10px;
 }
 
 /* Invalid form popup */
 #invalid-form-popup {
   -moz-appearance: none;
   background-color: #fffcd6;
   border: 1px solid #dad8b6;
-  padding: 5px 5px 5px 5px;
   font-weight: bold;
 }
 
 /* Notification popup */
 #notification-popup {
   margin: 4px 0;
   min-width: 280px;
   padding: 10px;

--- a/browser/themes/pinstripe/browser/browser.css
+++ b/browser/themes/pinstripe/browser/browser.css
@@ -2026,25 +2026,16 @@ toolbarbutton.chevron > .toolbarbutton-m
   -moz-window-shadow: none;
   background-color: transparent;
   margin-top: -3px;
   margin-left: -23px;
   min-width: 280px;
   -moz-border-image: url(chrome://browser/skin/hud-panel.png) 26 18 22 50 / 26px 18px 22px 50px repeat;
 }
 
-/* Invalid form popup */
-#invalid-form-popup {
-  -moz-appearance: none;
-  background-color: #fffcd6;
-  border: 1px solid #dad8b6;
-  padding: 5px 5px 5px 5px;
-  font-weight: bold;
-}
-
 #notification-popup {
   margin-left: -16px;
   margin-right: -16px;
 }
 
 #notification-popup-box {
   margin: 0 3px;
 }

--- a/browser/themes/winstripe/browser/browser.css
+++ b/browser/themes/winstripe/browser/browser.css
@@ -1854,25 +1854,16 @@ toolbarbutton.bookmark-item[dragover="tr
 }
 
 /* Popup Bounding Box */
 #identity-popup {
   -moz-appearance: menupopup;
   color: MenuText;
 }
 
-/* Invalid form popup */
-#invalid-form-popup {
-  -moz-appearance: none;
-  background-color: #fffcd6;
-  border: 1px solid #dad8b6;
-  padding: 5px 5px 5px 5px;
-  font-weight: bold;
-}
-
 /* Notification popup */
 #notification-popup {
   padding: 10px;
 }
 
 .popup-notification-icon {
   width: 64px;
   height: 64px;