diff --git a/_config.yml b/_config.yml
index 041c32e..a0b0731 100644
--- a/_config.yml
+++ b/_config.yml
@@ -4,6 +4,7 @@ theme: jekyll-theme-Hacker
 markdown: kramdown
 
 kramdown:
+  input: GFM
   math_engine: mathjax