diff --git a/cheetah/Template.py b/cheetah/Template.py
index 7a9d0a75..27cf3929 100644
--- a/cheetah/Template.py
+++ b/cheetah/Template.py
@@ -1171,7 +1171,7 @@ def __init__(self, source=None,
         if not isinstance(source, (types.NoneType, basestring)):
             raise TypeError(errmsg % ('source', 'string or None'))
 
-        if not isinstance(source, (types.NoneType, basestring, filetype)):
+        if not isinstance(file, (types.NoneType, basestring, filetype)):
             raise TypeError(errmsg %
                             ('file', 'string, file open for reading, or None'))