diff --git a/syntax/sass.vim b/syntax/sass.vim
index a1d55b8..1eab274 100644
--- a/syntax/sass.vim
+++ b/syntax/sass.vim
@@ -29,7 +29,7 @@ syn match sassFunction "\<\%(unquote\|quote\)\>(\@=" contained
 syn match sassFunction "\<\%(percentage\|round\|ceil\|floor\|abs\)\>(\@=" contained
 syn match sassFunction "\<\%(type-of\|unit\|unitless\|comparable\)\>(\@=" contained
 
-syn match sassMixinName "\w\+" contained nextgroup=sassCssAttribute
+syn match sassMixinName "[[:alnum:]_-]\+" contained nextgroup=sassCssAttribute
 syn match sassMixin  "^="               nextgroup=sassMixinName
 syn match sassMixin  "^@mixin"          nextgroup=sassMixinName skipwhite
 syn match sassMixing "^\s\+\zs+"        nextgroup=sassMixinName