diff --git a/vcr/stubs/__init__.py b/vcr/stubs/__init__.py
index b372658..a703ff4 100644
--- a/vcr/stubs/__init__.py
+++ b/vcr/stubs/__init__.py
@@ -191,7 +191,8 @@ class VCRConnection(object):
         body of the request.  So if that happens, let's just append the data
         onto the most recent request in the cassette.
         '''
-        self._vcr_request.body = (self._vcr_request.body or '') + data
+        self._vcr_request.body = self._vcr_request.body + data \
+            if self._vcr_request.body else data
 
     def close(self):
         # Note: the real connection will only close if it's open, so