diff --git a/Control/Concurrent/STM/TVar.hs b/Control/Concurrent/STM/TVar.hs
--- a/Control/Concurrent/STM/TVar.hs
+++ b/Control/Concurrent/STM/TVar.hs
@@ -31,6 +31,6 @@
 import Control.Sequential.STM
 #endif
 
-#if ! MIN_VERSION_base(4,2,0)
+#if ! (MIN_VERSION_base(4,2,0))
 readTVarIO = atomically . readTVar
 #endif
diff --git a/stm.cabal b/stm.cabal
--- a/stm.cabal
+++ b/stm.cabal
@@ -1,5 +1,5 @@
 name:		stm
-version:	2.1.2.1
+version:	2.1.2.2
 license:	BSD3
 license-file:	LICENSE
 maintainer:	libraries@haskell.org