diff --git a/Yesod/Test/Json.hs b/Yesod/Test/Json.hs
--- a/Yesod/Test/Json.hs
+++ b/Yesod/Test/Json.hs
@@ -10,7 +10,8 @@
 	Session(..),
 	H.Assertion,
 	module Test.Hspec,
-	module Data.Aeson
+	module Data.Aeson,
+        SResponse(..)
 	) where
 import qualified Test.HUnit as H
 import qualified Data.ByteString.Lazy.Char8 as L8
@@ -28,9 +29,9 @@
 
 -- | A request to your server. 
 type APIFunction = ByteString -- ^ method
-				   -> [Text] -- ^ path
-				   -> Value -- JSON data
-				   -> Session SResponse
+                   -> [Text] -- ^ path
+                   -> Maybe Value -- JSON data
+                   -> Session SResponse
 
 -- Assert a boolean value
 assertBool :: String -> Bool -> Session ()
@@ -63,7 +64,7 @@
 
 -- | Make a request to your server
 apiRequest :: AppConfig env extra -> APIFunction
-apiRequest conf m p x = srequest $ SRequest r (encode x) where
+apiRequest conf m p x = srequest $ SRequest r (maybe L.empty encode x) where
     r = defaultRequest {
         serverPort = appPort conf,
         requestBody = sourceList . L.toChunks $ encode x,
diff --git a/yesod-test-json.cabal b/yesod-test-json.cabal
--- a/yesod-test-json.cabal
+++ b/yesod-test-json.cabal
@@ -2,7 +2,7 @@
 -- documentation, see http://haskell.org/cabal/users-guide/
 
 name:                yesod-test-json
-version:             0.1.0.0
+version:             0.2.0.0
 synopsis:            Utility functions for testing JSON web services written in Yesod
 description:         yesod-test-json provides combinators for using the hspec and wai-test libraries together.
                      It is meant to be used like yesod-test, but for web services as opposed to web applications.
@@ -22,4 +22,4 @@
 library
   exposed-modules:     Yesod.Test.Json
   -- other-modules:       
-  build-depends:       base ==4.5.*, HUnit ==1.2.*, bytestring ==0.9.*, text ==0.11.*, aeson ==0.6.*, http-types ==0.6.*, hspec ==1.3.*, wai ==1.2.*, wai-test ==1.2.*, transformers ==0.3.*, yesod-default ==1.0.*, conduit ==0.4.*
+  build-depends:       base ==4.5.*, HUnit ==1.2.*, bytestring ==0.9.*, text ==0.11.*, aeson, http-types, hspec, wai, wai-test, transformers ==0.3.*, yesod-default, conduit