diff --git a/six.py b/six.py
index 4e15675d..0315fde1 100644
--- a/six.py
+++ b/six.py
@@ -913,6 +913,11 @@ def ensure_binary(s, encoding='utf-8', errors='strict'):
     raise TypeError("not expecting type '%s'" % type(s))
 
 
+def ensure_bytes(s, encoding='utf-8', errors='strict'):
+    """Alias of ensure_binary"""
+    return ensure_binary(s, encoding, errors)
+
+
 def ensure_str(s, encoding='utf-8', errors='strict'):
     """Coerce *s* to `str`.