diff --git a/plugin/NERD_commenter.vim b/plugin/NERD_commenter.vim
index eeec642..b3060bb 100644
--- a/plugin/NERD_commenter.vim
+++ b/plugin/NERD_commenter.vim
@@ -705,7 +705,7 @@ function s:CommentBlock(top, bottom, lSide, rSide, forceNested )
     "alternative delimiters (if THEY are) as the comment will be better and more
     "accurate with multipart delimiters
     let switchedDelims = 0
-    if !s:Multipart() && g:NERDAllowAnyVisualDelims && s:AltMultipart()
+    if !s:Multipart() && !g:NERDAllowAnyVisualDelims && s:AltMultipart()
         let switchedDelims = 1
         call s:SwitchToAlternativeDelimiters(0)
     endif