diff --git a/yesod-form/Yesod/Form/Fields.hs b/yesod-form/Yesod/Form/Fields.hs
index 7917ce27..adc59deb 100644
--- a/yesod-form/Yesod/Form/Fields.hs
+++ b/yesod-form/Yesod/Form/Fields.hs
@@ -328,7 +328,7 @@ $newline never
 <script>if (!('autofocus' in document.createElement('input'))) {document.getElementById('#{theId}').focus();}
 |]
           toWidget [cassius|
-            #{theId}
+            ##{theId}
               -webkit-appearance: textfield
             |]
     , fieldEnctype = UrlEncoded