diff --git a/vcr/matchers.py b/vcr/matchers.py
index 57e7a02d..73492924 100644
--- a/vcr/matchers.py
+++ b/vcr/matchers.py
@@ -49,7 +49,8 @@ def _transform_json(body):
     # Request body is always a byte string, but json.loads() wants a text
     # string. RFC 7159 says the default encoding is UTF-8 (although UTF-16
     # and UTF-32 are also allowed: hmmmmm).
-    return json.loads(body.decode('utf-8'))
+    if body:
+        return json.loads(body.decode('utf-8'))
 
 
 _xml_header_checker = _header_checker('text/xml')