Fixes issue 133.
diff --git a/python2/httplib2/__init__.py b/python2/httplib2/__init__.py
index d9f38d9..f3801b7 100644
--- a/python2/httplib2/__init__.py
+++ b/python2/httplib2/__init__.py
@@ -932,7 +932,7 @@
         self.connections = {}
         # The location of the cache, for now a directory
         # where cached responses are held.
-        if cache and isinstance(cache, str):
+        if cache and isinstance(cache, basestring):
             self.cache = FileCache(cache)
         else:
             self.cache = cache