diff --git a/Control/Concurrent/CHP/Clocks.hs b/Control/Concurrent/CHP/Clocks.hs
--- a/Control/Concurrent/CHP/Clocks.hs
+++ b/Control/Concurrent/CHP/Clocks.hs
@@ -118,7 +118,7 @@
 module Control.Concurrent.CHP.Clocks (Clock, Waitable(..),
   waitUnbounded, newClock, newClockWithLabel) where
 
-import Control.Concurrent.STM
+import Control.Concurrent.STM (STM, TVar, atomically, newTVar, readTVar, writeTVar)
 import Control.Monad hiding (mapM, mapM_)
 import Data.Foldable (mapM_)
 -- Needed for testing:
diff --git a/chp.cabal b/chp.cabal
--- a/chp.cabal
+++ b/chp.cabal
@@ -1,5 +1,5 @@
 Name:            chp
-Version:         2.2.0
+Version:         2.2.0.1
 Synopsis:        An implementation of concurrency ideas from Communicating Sequential Processes
 License:         BSD3
 License-file:    LICENSE
@@ -23,9 +23,11 @@
 
 Cabal-Version:   >= 1.2.3
 Build-Type:      Simple
-Build-Depends:   base >= 3 && < 5, containers, deepseq >= 1.1 && < 1.2, extensible-exceptions >= 0.1.1.0, pretty, stm
 
-Exposed-modules: Control.Concurrent.CHP
+Library
+  Build-Depends:   base >= 3 && < 5, containers, deepseq >= 1.1, extensible-exceptions >= 0.1.1.0, pretty, stm
+
+  Exposed-modules: Control.Concurrent.CHP
                  Control.Concurrent.CHP.Alt
                  Control.Concurrent.CHP.Barriers
                  Control.Concurrent.CHP.Channels
@@ -44,7 +46,7 @@
                  Control.Concurrent.CHP.Traces.TraceOff
                  Control.Concurrent.CHP.Traces.VCR
 
-Other-modules:   Control.Concurrent.CHP.Base
+  Other-modules:   Control.Concurrent.CHP.Base
                  Control.Concurrent.CHP.Channels.Base
                  Control.Concurrent.CHP.CSP                 
                  Control.Concurrent.CHP.Event
@@ -57,7 +59,7 @@
                  Control.Concurrent.CHP.ProcessId
                  Control.Concurrent.CHP.Traces.Base
 
-Extensions:      BangPatterns CPP FlexibleInstances
+  Extensions:      BangPatterns CPP FlexibleInstances
                  MultiParamTypeClasses Rank2Types ScopedTypeVariables
 
-GHC-Options:     -Wall -auto-all
+  GHC-Options:     -Wall -auto-all