diff --git a/dotfiles/lib/python/knight_moves_count.py b/dotfiles/lib/python/knight_moves_count.py
old mode 100644
new mode 100755
index a2de26f9..2e1f131c
--- a/dotfiles/lib/python/knight_moves_count.py
+++ b/dotfiles/lib/python/knight_moves_count.py
@@ -1,3 +1,4 @@
+#!/usr/bin/env python
 import sys