diff --git a/github_deploy/main.py b/github_deploy/main.py
index bec9463..2acef84 100644
--- a/github_deploy/main.py
+++ b/github_deploy/main.py
@@ -17,10 +17,14 @@ def list_commands(self, ctx):
     def get_command(self, ctx, name):
         ns = {}
         fn = os.path.join(plugin_folder, name + '.py')
-        with open(fn) as f:
-            code = compile(f.read(), fn, 'exec')
-            eval(code, ns, ns)
-        return ns['main']
+
+        if os.path.exists(fn):
+            with open(fn) as f:
+                code = compile(f.read(), fn, 'exec')
+                eval(code, ns, ns)
+            return ns['main']
+
+        ctx.fail("Invalid Command: {name}".format(name=name))
 
 
 main = GithubDeploy(