diff --git a/fix_xc7_carry.py b/fix_xc7_carry.py
old mode 100644
new mode 100755
index 9b911dcb..f457c836
--- a/fix_xc7_carry.py
+++ b/fix_xc7_carry.py
@@ -1,3 +1,5 @@
+#!/usr/bin/env python3
+
 """ Script for addressing CARRY4 output congestion in elaborated netlists.
 
 Usage: