diff --git a/mstate.cabal b/mstate.cabal
--- a/mstate.cabal
+++ b/mstate.cabal
@@ -8,12 +8,16 @@
 Author:         Nils Schweinsberg
 Maintainer:     <mail@n-sch.de>
 
-Version:        0.2.3
+Version:        0.2.4
 Category:       Concurrency, Monads
 License:        BSD3
 License-File:   LICENSE
 Cabal-Version:  >= 1.6
 Build-Type:     Simple
+
+source-repository head
+    type: git
+    location: https://github.com/mcmaniac/mstate.git
 
 Library
     GHC-Options:        -Wall
diff --git a/src/Control/Concurrent/MState.hs b/src/Control/Concurrent/MState.hs
--- a/src/Control/Concurrent/MState.hs
+++ b/src/Control/Concurrent/MState.hs
@@ -32,6 +32,7 @@
     , forkM
     , forkM_
     , killMState
+    , waitM
 
       -- * Example
       -- $example
@@ -197,6 +198,17 @@
     _ <- liftIO . forkIO $
       mapM_ (killThread . fst) tms
     return ()
+
+-- | Wait for a thread to finish
+waitM :: MonadPeelIO m => ThreadId -> MState t m ()
+waitM tid = MState $ \(_,c) -> do
+    mw <- liftIO . atomically $ do
+        lookup tid `fmap` readTVar c
+    maybe (return ()) wait' mw
+  where
+    wait' w = liftIO . atomically $ do
+        () <- takeTMVar w
+        putTMVar w () -- clean up again for "waitForTermination"
 
 --------------------------------------------------------------------------------
 -- Monad instances