diff --git a/pyvpn b/pyvpn
index 4f3b202..6439627 100755
--- a/pyvpn
+++ b/pyvpn
@@ -52,7 +52,7 @@ if len(sys.argv) > 2:
         
         if prog == "/usr/bin/revoke-vpn-user\n":
 
-            os.System(prog + " " + sys.argv[2])
+            os.system(prog + " " + sys.argv[2])
         else:
             sys.stdout.write("Error! This system is not ready for client revocation yet. Please try again later.")
             sys.stdout.flush()