diff --git a/rest_framework/test.py b/rest_framework/test.py
index f89a6dcd0..9b40353a3 100644
--- a/rest_framework/test.py
+++ b/rest_framework/test.py
@@ -36,7 +36,7 @@ class APIRequestFactory(DjangoRequestFactory):
         Encode the data returning a two tuple of (bytes, content_type)
         """
 
-        if not data:
+        if data is None:
             return ('', content_type)
 
         assert format is None or content_type is None, (