diff --git a/changelog.md b/changelog.md
--- a/changelog.md
+++ b/changelog.md
@@ -1,3 +1,13 @@
+__v0.9.10__
+
+avoid pre-lifting IO into MonadIO
+
+extend aeson upper-bound
+
+__v0.9.9__
+
+generalize (Either PinboardError a) to (MonadErrorPinboard)
+
 __v0.9.8__
 
 use safe-exception
diff --git a/pinboard.cabal b/pinboard.cabal
--- a/pinboard.cabal
+++ b/pinboard.cabal
@@ -1,5 +1,5 @@
 name:                pinboard
-version:             0.9.9
+version:             0.9.10
 synopsis:            Access to the Pinboard API
 license:             MIT
 license-file:        LICENSE
@@ -23,7 +23,7 @@
 library 
   hs-source-dirs:      src
   build-depends:       base >=4.6 && < 5.0
-                     , aeson >= 0.11.1  && <0.12
+                     , aeson >= 0.11.1  && < 2.0
                      , bytestring >= 0.10.0  && <0.11 
                      , containers >= 0.5.0.0 && <0.6 
                      , either >= 4.4.1 && < 4.5
diff --git a/src/Pinboard/Client.hs b/src/Pinboard/Client.hs
--- a/src/Pinboard/Client.hs
+++ b/src/Pinboard/Client.hs
@@ -91,7 +91,7 @@
     -> PinboardT m a
     -> m (e a)
 runPinboard config f = do
-  mgr <- newMgr
+  mgr <- liftIO newMgr
   eitherToMonadError <$> runPinboardT (config, mgr) f
                    
 
@@ -102,57 +102,55 @@
     -> m a
 pinboardJson req = do 
   env <- ask
-  res <- sendPinboardRequest env (ensureResultFormatType FormatJson req)
+  res <- liftIO $ sendPinboardRequest env (ensureResultFormatType FormatJson req)
   eitherToMonadThrow (parseJSONResponse res)
 
 --------------------------------------------------------------------------------
 
 runPinboardSingleRaw
-    :: MonadIO m
-    => PinboardConfig       
+    :: PinboardConfig       
     -> PinboardRequest
-    -> m (Response LBS.ByteString)
+    -> IO (Response LBS.ByteString)
 runPinboardSingleRaw config req = liftIO $ newMgr >>= go
   where go mgr = sendPinboardRequest (config, mgr) req
 
 runPinboardSingleRawBS
-    :: (MonadIO m, MonadErrorPinboard e)
+    :: (MonadErrorPinboard e)
     => PinboardConfig       
     -> PinboardRequest
-    -> m (e LBS.ByteString)
+    -> IO (e LBS.ByteString)
 runPinboardSingleRawBS config req = do
   res <- runPinboardSingleRaw config req
   return $ responseBody res <$ checkStatusCodeResponse res
 
 runPinboardSingleJson
-      :: (MonadIO m, MonadCatch m, MonadErrorPinboard e, FromJSON a)
+      :: (MonadErrorPinboard e, FromJSON a)
       => PinboardConfig       
       -> PinboardRequest
-      -> m (e a)
+      -> IO (e a)
 runPinboardSingleJson config = runPinboard config . pinboardJson
 
 
 --------------------------------------------------------------------------------
 
 sendPinboardRequest
-      :: MonadIO m
-      => PinboardEnv
+      :: PinboardEnv
       -> PinboardRequest 
-      -> m (Response LBS.ByteString)
+      -> IO (Response LBS.ByteString)
 sendPinboardRequest (PinboardConfig{..}, mgr) PinboardRequest{..} = do
    let url = T.concat [ requestPath 
                       , "?" 
                       , T.decodeUtf8 $ paramsToByteString $ ("auth_token", urlEncode False apiToken) : encodeParams requestParams ]
    req <- buildReq $ T.unpack url
-   liftIO $ httpLbs req mgr
+   httpLbs req mgr
 
 --------------------------------------------------------------------------------
 
-buildReq :: MonadIO m => String -> m Request
+buildReq :: String -> IO Request
 buildReq url = do
-  req <- liftIO $ parseRequest $ "https://api.pinboard.in/v1/" <> url
+  req <- parseRequest $ "https://api.pinboard.in/v1/" <> url
   return $ setRequestIgnoreStatus $ req { 
-    requestHeaders = [("User-Agent","pinboard.hs/0.9.9")]
+    requestHeaders = [("User-Agent","pinboard.hs/0.9.10")]
     }
 
 --------------------------------------------------------------------------------
@@ -210,9 +208,9 @@
 --------------------------------------------------------------------------------
 
 
-newMgr :: MonadIO m => m Manager
-newMgr = liftIO $ withSocketsDo . newManager 
-                $ managerSetProxy (proxyEnvironment Nothing) tlsManagerSettings
+newMgr :: IO Manager
+newMgr = withSocketsDo . newManager 
+           $ managerSetProxy (proxyEnvironment Nothing) tlsManagerSettings
 
 mgrFail :: (Monad m, MonadErrorPinboard e) => PinboardErrorType -> SomeException -> m (e b)
 mgrFail e msg = return $ throwError $ PinboardError e (toText msg) Nothing Nothing Nothing
diff --git a/tests/Test.hs b/tests/Test.hs
--- a/tests/Test.hs
+++ b/tests/Test.hs
@@ -31,26 +31,23 @@
     propJSONApproxEq (Proxy :: Proxy PostDates)
 
     describe "decodeJSONResponse: handle parse failures" $ do
-        it "object parse failure" $
+        it "malformed object parses as ParseFailure" $
             let noteJson = "FAIL"
             in case decodeJSONResponse noteJson of
             Left PinboardError{..} -> errorType == ParseFailure
             Right Note{..} -> False
-        it "field parse failure" $
+        it "malformed field parses as ParseFailure" $
             let noteJson = "{\"length\":0,\"hash\":\"\",\"text_FAIL\":\"\",\"updated_at\":\"1864-05-09 13:50:53\",\"created_at\":\"1864-05-09 18:21:35\",\"id\":\"\",\"title\":\"\"}"
             in case decodeJSONResponse noteJson of
             Left PinboardError{..} -> errorType == ParseFailure
             Right Note{..} -> False
-        it "value parse failure" $
-            let noteJson = "{\"length\":FAIL,\"hash\":\"\",\"text_FAIL\":\"\",\"updated_at\":\"1864-05-09 13:50:53\",\"created_at\":\"1864-05-09 18:21:35\",\"id\":\"\",\"title\":\"\"}"
+        it "malformed value parses as ParseFailure" $
+            let noteJson = "{\"length\":FAIL,\"hash\":\"\",\"text\":\"\",\"updated_at\":\"1864-05-09 13:50:53\",\"created_at\":\"1864-05-09 18:21:35\",\"id\":\"\",\"title\":\"\"}"
             in case decodeJSONResponse noteJson of
             Left PinboardError{..} -> errorType == ParseFailure
             Right Note{..} -> False
-        it "time parse failure" $
+        it "malformed time parses as ParseFailure" $
             let noteJson = "{\"length\":0,\"hash\":\"\",\"text\":\"\",\"updated_at\":\"FAIL-05-09 13:50:53\",\"created_at\":\"1864-05-09 18:21:35\",\"id\":\"\",\"title\":\"\"}"
             in case decodeJSONResponse noteJson of
             Left PinboardError{..} -> errorType == ParseFailure
             Right Note{..} -> False
-
-pinboardParseFailure :: Selector PinboardError
-pinboardParseFailure e = errorType e == ParseFailure