diff --git a/stegano/basic.py b/stegano/basic.py
index 88569fe..902c8ca 100755
--- a/stegano/basic.py
+++ b/stegano/basic.py
@@ -24,6 +24,8 @@ __version__ = "$Revision: 0.1 $"
 __date__ = "$Date: 2010/10/01 $"
 __license__ = "GPLv3"
 
+import sys
+
 from PIL import Image
 
 def hide(img, message):
@@ -103,4 +105,4 @@ if __name__ == '__main__':
 
     elif sys.argv[1] == "reveal":
         img = Image.open(options.input_image_file)
-        print reveal(img)
\ No newline at end of file
+        print reveal(img)