diff --git a/lib/maruku/ext/math/mathml_engines/blahtex.rb b/lib/maruku/ext/math/mathml_engines/blahtex.rb
index 4acd536..4edf8c1 100644
--- a/lib/maruku/ext/math/mathml_engines/blahtex.rb
+++ b/lib/maruku/ext/math/mathml_engines/blahtex.rb
@@ -55,7 +55,7 @@ def convert_to_png_blahtex(kind, tex)
     md5 = md5.text
 
     PNG.new("#{get_setting(:html_png_url)}#{md5}.png", depth, height)
-  rescue x=> e
+  rescue => e
     maruku_error "Error: #{e}"
   end