diff --git a/convert.rb b/convert.rb
index bbcbd00..87af9ba 100644
--- a/convert.rb
+++ b/convert.rb
@@ -28,7 +28,7 @@ class KatexRenderer
     rendered = content.gsub /\\\(((?:[^\\]|\\[^\)])*)\\\)/ do |match|
       render(false, $~[1])
     end
-    rendered = rendered.gsub /\$\$((?:[^\$]|$[^\$])*)\$\$/ do |match|
+    rendered = rendered.gsub /\$\$(.*?)\$\$/ do |match|
       render(true, $~[1])
     end
     return rendered