diff --git a/src/User.py b/src/User.py
index 6048f1b66..8fbfd4e0b 100755
--- a/src/User.py
+++ b/src/User.py
@@ -222,7 +222,11 @@ class User(callbacks.Privmsg):
             pass
         if not user.checkPassword(password) and \
            not user.checkHostmask(msg.prefix):
-            u = ircdb.users.getUser(msg.prefix)
+            try:
+                u = ircdb.users.getUser(msg.prefix)
+            except KeyError:
+                irc.error(conf.supybot.replies.incorrectAuthentication())
+                return
             if not u.checkCapability('owner'):
                 irc.error(conf.supybot.replies.incorrectAuthentication())
                 return