diff --git a/ayrton/tests/test_ayrton.py b/ayrton/tests/test_ayrton.py
index <HASH>..<HASH> 100644
--- a/ayrton/tests/test_ayrton.py
+++ b/ayrton/tests/test_ayrton.py
@@ -518,6 +518,17 @@ def foo ():
 
 foo ()''')
 
+    def testUnknown (self):
+        try:
+            ayrton.main ('''foo''')
+        except CommandNotFound:
+            raise
+        except NameError:
+            pass
+        self.assertRaises (NameError, ayrton.main, '''fff()''')
+        self.assertRaises (CommandNotFound, ayrton.main, '''fff()''')
+        # ayrton.main ('print (globals ())')
+
 class ParsingErrors (unittest.TestCase):
 
     def testTupleAssign (self):
[+] test for uknown names/commands.