diff --git a/source/Network/Xmpp/Concurrent.hs b/source/Network/Xmpp/Concurrent.hs
index 3881cd8..1fa0c90 100644
--- a/source/Network/Xmpp/Concurrent.hs
+++ b/source/Network/Xmpp/Concurrent.hs
@@ -97,17 +97,12 @@ newSession stream config = runErrorT $ do
     let stanzaHandler = toChans stanzaChan outC iqHandlers
     (kill, wLock, streamState, readerThread) <- ErrorT $ startThreadsWith stanzaHandler eh stream
     writer <- lift $ forkIO $ writeWorker outC wLock
-    idRef <- lift $ newTVarIO 1
-    let getId = atomically $ do
-            curId <- readTVar idRef
-            writeTVar idRef (curId + 1 :: Integer)
-            return . read. show $ curId
     return $ Session { stanzaCh = stanzaChan
                      , outCh = outC
                      , iqHandlers = iqHandlers
                      , writeRef = wLock
                      , readerThread = readerThread
-                     , idGenerator = getId
+                     , idGenerator = sessionStanzaIDs config
                      , streamRef = streamState
                      , eventHandlers = eh
                      , stopThreads = kill >> killThread writer
diff --git a/source/Network/Xmpp/Types.hs b/source/Network/Xmpp/Types.hs
index a878db4..c230b06 100644
--- a/source/Network/Xmpp/Types.hs
+++ b/source/Network/Xmpp/Types.hs
@@ -1095,8 +1095,15 @@ data SessionConfiguration = SessionConfiguration
       sessionStreamConfiguration :: StreamConfiguration
       -- | Handler to be run when the session ends (for whatever reason).
     , sessionClosedHandler :: XmppFailure -> IO ()
+    , sessionStanzaIDs :: IO StanzaID
     }
 
 instance Default SessionConfiguration where
     def = SessionConfiguration { sessionStreamConfiguration = def
-                               , sessionClosedHandler = \_ -> return () }
+                               , sessionClosedHandler = \_ -> return ()
+                               , sessionStanzaIDs = do
+                                     idRef <- newTVarIO 1
+                                     atomically $ do
+                                         curId <- readTVar idRef
+                                         writeTVar idRef (curId + 1 :: Integer)
+                                         return . read. show $ curId}