diff --git a/ChangeLog.md b/ChangeLog.md
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,3 +1,7 @@
+# 1.0.5
+
+* Fix a bug in the `jsonAjax` implementation: the request body was not properly JSON encoded.
+
 # 1.0.4
 
 * Add helper functions `ajax` and `jsonAjax` to `React.Flux.Combinators` to assist with sending
diff --git a/react-flux.cabal b/react-flux.cabal
--- a/react-flux.cabal
+++ b/react-flux.cabal
@@ -1,5 +1,5 @@
 name:                react-flux
-version:             1.0.4
+version:             1.0.5
 synopsis:            A binding to React based on the Flux application architecture for GHCJS
 category:            Web
 homepage:            https://bitbucket.org/wuzzeb/react-flux
diff --git a/src/React/Flux/Combinators.hs b/src/React/Flux/Combinators.hs
--- a/src/React/Flux/Combinators.hs
+++ b/src/React/Flux/Combinators.hs
@@ -227,7 +227,7 @@
 -- >    type StoreAction MyStore = MyStoreAction
 -- >
 -- >    transform (LaunchTheMissiles t) s = do
--- >        jsonAjax "PUT" "/launch-the-missiles" [] t $ \case ->
+-- >        jsonAjax "PUT" "/launch-the-missiles" [] t $ \case
 -- >            Left (_, msg) -> return [SomeStoreAction myStore $ UnableToLaunchMissiles msg]
 -- >            Right traj -> return [SomeStoreAction myStore $ MissilesLaunched traj]
 -- >        return s { launchUpdate = UpdatePending ("Requesting missle launch against " ++ T.pack (show t)) }
@@ -257,7 +257,8 @@
 jsonAjax :: (ToJSON body, FromJSON response)
          => Text -- ^ the method
          -> Text -- ^ the URI
-         -> [(Text, Text)] -- ^ the headers
+         -> [(Text, Text)] -- ^ the headers.  In addition to these headers, 'jsonAjax' adds two headers:
+                           -- @Content-Type: application/json@ and @Accept: application/json@.
          -> body -- ^ the body
          -> (Either (Int, Text) response -> IO [SomeStoreAction])
             -- ^ Once @XMLHttpRequest@ changes the @readyState@ to done this handler will be
@@ -273,11 +274,12 @@
          -> IO ()
 #ifdef __GHCJS__
 jsonAjax method uri headers body handler = do
-    bodyRef <- toJSVal_aeson body
+    bodyRef <- toJSVal_aeson body >>= js_JSONstringify
+    let extraHeaders = [("Content-Type", "application/json"), ("Accept", "application/json")]
     let req = AjaxRequest
               { reqMethod = JSS.textToJSString method
               , reqURI = JSS.textToJSString uri
-              , reqHeaders = map (JSS.textToJSString *** JSS.textToJSString) headers
+              , reqHeaders = extraHeaders ++ map (JSS.textToJSString *** JSS.textToJSString) headers
               , reqBody = bodyRef
               }
     ajax req $ \resp ->
@@ -307,6 +309,10 @@
 foreign import javascript unsafe
     "JSON['parse']($1)"
     js_JSONParse :: JSString -> IO JSVal
+
+foreign import javascript unsafe
+    "JSON['stringify']($1)"
+    js_JSONstringify :: JSVal -> IO JSVal
 
 foreign import javascript unsafe
     "$1.hs"