diff --git a/marconi/tests/transport/wsgi/test_messages.py b/marconi/tests/transport/wsgi/test_messages.py
index 75a60a174..570e71677 100644
--- a/marconi/tests/transport/wsgi/test_messages.py
+++ b/marconi/tests/transport/wsgi/test_messages.py
@@ -119,6 +119,15 @@ class MessagesBaseTest(base.TestBase):
 
             self.assertEquals(self.srmock.status, falcon.HTTP_400)
 
+    def test_unsupported_json(self):
+        for document in ('{"overflow": 9223372036854775808}',
+                         '{"underflow": -9223372036854775809}'):
+            self.simulate_post(self.queue_path + '/messages',
+                               body=document,
+                               headers=self.headers)
+
+            self.assertEquals(self.srmock.status, falcon.HTTP_400)
+
     def test_delete(self):
         path = self.queue_path + '/messages'
         self._post_messages(path)
diff --git a/marconi/transport/helpers.py b/marconi/transport/helpers.py
index bb7771570..f052f3d8f 100644
--- a/marconi/transport/helpers.py
+++ b/marconi/transport/helpers.py
@@ -21,6 +21,20 @@ class MalformedJSON(ValueError):
     pass
 
 
+class OverflowedJSONInteger(OverflowError):
+    """JSON integer is too large."""
+    pass
+
+
+def _json_int(s):
+    """Parse a string as a base 10 64-bit signed integer."""
+    i = int(s)
+    if not (int(-2 ** 63) <= i <= int(2 ** 63 - 1)):
+        raise OverflowedJSONInteger()
+
+    return i
+
+
 def read_json(stream, len):
     """Like json.load, but converts ValueError to MalformedJSON upon failure.
 
@@ -28,7 +42,7 @@ def read_json(stream, len):
     :param len: the number of bytes to read from stream
     """
     try:
-        return json.loads(stream.read(len))
+        return json.loads(stream.read(len), parse_int=_json_int)
 
     except ValueError as ex:
         raise MalformedJSON(ex)
diff --git a/marconi/transport/wsgi/helpers.py b/marconi/transport/wsgi/helpers.py
index 930f95499..efc78eb4e 100644
--- a/marconi/transport/wsgi/helpers.py
+++ b/marconi/transport/wsgi/helpers.py
@@ -62,6 +62,11 @@ def filter_stream(stream, len, spec, doctype=JSONObject):
         description = _('Body could not be parsed.')
         raise exceptions.HTTPBadRequestBody(description)
 
+    except helpers.OverflowedJSONInteger as ex:
+        LOG.exception(ex)
+        description = _('JSON contains integer that is too large.')
+        raise exceptions.HTTPBadRequestBody(description)
+
     except Exception as ex:
         # Error while reading from the network/server
         LOG.exception(ex)