diff --git a/block.py b/block.py
old mode 100644
new mode 100755
index 832e7ad..01a65e7
--- a/block.py
+++ b/block.py
@@ -1,3 +1,5 @@
+#!/usr/bin/env python
+
 import math
 from lib.input import *
 from lib.vars import alphabet
diff --git a/caesar.py b/caesar.py
old mode 100644
new mode 100755
index 1013148..24f10a2
--- a/caesar.py
+++ b/caesar.py
@@ -1,3 +1,5 @@
+#!/usr/bin/env python
+
 from lib.input import *
 from lib.vars import alphabet
 from lib.vars import listToString