diff --git a/lib/jekyll/tags/gist.rb b/lib/jekyll/tags/gist.rb
index efeb62c3..0b40a5fd 100644
--- a/lib/jekyll/tags/gist.rb
+++ b/lib/jekyll/tags/gist.rb
@@ -7,7 +7,7 @@
 module Jekyll
   class GistTag < Liquid::Tag
     def render(context)
-      if tag_contents = @markup.match(/(\d+) (.*)/)
+      if tag_contents = @markup.strip.match(/\A(\d+) ?(\S*)\z/)
         gist_id, filename = tag_contents[1].strip, tag_contents[2].strip
         gist_script_tag(gist_id, filename)
       else