diff --git a/mockredis/client.py b/mockredis/client.py
index 926e048..aecd4a9 100644
--- a/mockredis/client.py
+++ b/mockredis/client.py
@@ -155,6 +155,7 @@ def keys(self, pattern='*'):
         """Emulate keys."""
         # making sure the pattern is unicode/str.
         try:
+            pattern = self._encode(pattern)
             pattern = pattern.decode('utf-8')
             # This throws an AttributeError in python 3, or an
             # UnicodeEncodeError in python 2