diff --git a/vim/ftdetect/asciidoc.vim b/vim/ftdetect/asciidoc.vim
index 4180ab05af..08a43c6dd6 100644
--- a/vim/ftdetect/asciidoc.vim
+++ b/vim/ftdetect/asciidoc.vim
@@ -10,7 +10,7 @@
 " The first sets asciidoc syntax highlighting on all .txt files, the second
 " only existing files *.txt that appear to be AsciiDoc files.
 
-au BufNewFile,BufRead *.txt,README,TODO,CHANGELOG,NOTES  setfiletype asciidoc
+au BufNewFile,BufRead *.asc,*.asciidoc setfiletype asciidoc
 "au BufRead *.txt,README,TODO,CHANGELOG,NOTES call s:FTasciidoc()
 
 " This function checks for a valid AsciiDoc document title after first