diff --git a/after/syntax/css/css3-selectors.vim b/after/syntax/css/css3-selectors.vim
index 832d408..3f98e5a 100644
--- a/after/syntax/css/css3-selectors.vim
+++ b/after/syntax/css/css3-selectors.vim
@@ -2,4 +2,4 @@ syn keyword cssPseudoClassId contained target enabled disabled checked indetermi
 syn match cssPseudoClassId contained "\<first-of-type\>"
 syn match cssPseudoClassId contained "\<last-\(child\|of-type\)\>"
 syn match cssPseudoClassId contained "\<only-\(child\|of-type\)\>"
-syn region cssPseudoClassLang matchgroup=cssPseudoClassId start=":nth\(-last\)\?-\(child\|of-type\)(" end=")" oneline
+syn region cssPseudoClassLang matchgroup=cssPseudoClassId start=":\(nth\(-last\)\=-\(child\|of-type\)\|not\)(" end=")" oneline