diff --git a/UI/MailerUI/UIxMailFolderActions.m b/UI/MailerUI/UIxMailFolderActions.m
index 06f559cab..e04bf50bc 100644
--- a/UI/MailerUI/UIxMailFolderActions.m
+++ b/UI/MailerUI/UIxMailFolderActions.m
@@ -106,7 +106,7 @@
   keyForMsgUIDs = [NSString stringWithFormat:@"/%@/%@", currentAccount, currentMailbox];
 
   newFolderName = [[context request] formValueForKey: @"name"];
-  newKeyForMsgUIDs = [NSString stringWithFormat:@"/%@/folder%@", currentAccount, newFolderName];
+  newKeyForMsgUIDs = [[NSString stringWithFormat:@"/%@/folder%@", currentAccount, newFolderName] asCSSIdentifier];
   error = [co renameTo: newFolderName];
   if (error)
     {