diff --git a/mkdocs.yml b/mkdocs.yml
index 195df0e238a4501352d2fefd1ac2773bb792cdb4..5e20300ad8fff3b04dfc27e1bc28d1f1ef6299f1 100644
--- a/mkdocs.yml
+++ b/mkdocs.yml
@@ -189,7 +189,7 @@ extra:
     next: 'Next'
 
 markdown_extensions:
-  - codehilite(css_class=code)
+  - codehilite(css_class=code,linenums=true)
   - admonition
   - toc:
       permalink: '#'