diff --git a/syntax/markdown.vim b/syntax/markdown.vim
index ac48967..8010f4d 100644
--- a/syntax/markdown.vim
+++ b/syntax/markdown.vim
@@ -59,7 +59,7 @@ syn region markdownUrlTitle matchgroup=markdownUrlTitleDelimiter start=+(+ end=+
 syn region markdownLinkText matchgroup=markdownLinkTextDelimiter start="!\=\[\%(\_[^]]*]\%( \=[[(]\)\)\@=" end="\]\%( \=[[(]\)\@=" keepend nextgroup=markdownLink,markdownId skipwhite contains=@markdownInline,markdownLineStart
 syn region markdownLink matchgroup=markdownLinkDelimiter start="(" end=")" contains=markdownUrl keepend contained
 syn region markdownId matchgroup=markdownIdDelimiter start="\[" end="\]" keepend contained
-syn region markdownAutomaticLink matchgroup=markdownUrlDelimiter start="<\%(\w\+:\|\S\+@\)\@=" end=">" keepend oneline
+syn region markdownAutomaticLink matchgroup=markdownUrlDelimiter start="<\%(\w\+:\|[[:alnum:]_+-]\+@\)\@=" end=">" keepend oneline
 
 syn region markdownItalic start="\S\@<=\*\|\*\S\@=" end="\S\@<=\*\|\*\S\@=" keepend contains=markdownLineStart
 syn region markdownItalic start="\S\@<=_\|_\S\@=" end="\S\@<=_\|_\S\@=" keepend contains=markdownLineStart