diff --git a/Control/Concurrent/STM/TMVar.hs b/Control/Concurrent/STM/TMVar.hs
--- a/Control/Concurrent/STM/TMVar.hs
+++ b/Control/Concurrent/STM/TMVar.hs
@@ -159,6 +159,6 @@
 --
 -- @since 2.4.4
 mkWeakTMVar :: TMVar a -> IO () -> IO (Weak (TMVar a))
-mkWeakTMVar tmv@(TMVar (TVar t#)) f = IO $ \s ->
-    case mkWeak# t# tmv f s of (# s1, w #) -> (# s1, Weak w #)
+mkWeakTMVar tmv@(TMVar (TVar t#)) (IO finalizer) = IO $ \s ->
+    case mkWeak# t# tmv finalizer s of (# s1, w #) -> (# s1, Weak w #)
 #endif
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
@@ -76,5 +76,5 @@
 --
 -- @since 2.4.3
 mkWeakTVar :: TVar a -> IO () -> IO (Weak (TVar a))
-mkWeakTVar t@(TVar t#) f = IO $ \s ->
-    case mkWeak# t# t f s of (# s1, w #) -> (# s1, Weak w #)
+mkWeakTVar t@(TVar t#) (IO finalizer) = IO $ \s ->
+    case mkWeak# t# t finalizer s of (# s1, w #) -> (# s1, Weak w #)
diff --git a/changelog.md b/changelog.md
--- a/changelog.md
+++ b/changelog.md
@@ -1,5 +1,11 @@
 # Changelog for [`stm` package](http://hackage.haskell.org/package/stm)
 
+## 2.4.4.1  *Dec 2015*
+
+  * Add support for `base-4.9.0.0`
+
+  * Drop support for GHC 6.12 / `base-4.2`
+
 ## 2.4.4  *Dec 2014*
 
   * Add support for `base-4.8.0.0`
diff --git a/stm.cabal b/stm.cabal
--- a/stm.cabal
+++ b/stm.cabal
@@ -1,16 +1,16 @@
 name:           stm
-version:        2.4.4
+version:        2.4.4.1
 -- don't forget to update changelog.md file!
 license:        BSD3
 license-file:   LICENSE
 maintainer:     libraries@haskell.org
-bug-reports:    http://ghc.haskell.org/trac/ghc/newticket?component=libraries%20%28other%29&keywords=stm
+bug-reports:    https://ghc.haskell.org/trac/ghc/newticket?component=libraries%20%28other%29&keywords=stm
 synopsis:       Software Transactional Memory
 category:       Concurrency
 description:    A modular composable concurrency abstraction.
 build-type:     Simple
 cabal-version:  >=1.10
-tested-with:    GHC==7.6.3, GHC==7.6.2, GHC==7.6.1, GHC==7.4.2, GHC==7.4.1, GHC==7.2.2, GHC==7.2.1, GHC==7.0.4, GHC==7.0.3, GHC==7.0.2, GHC==7.0.1, GHC==6.12.3
+tested-with:    GHC==7.10.*, GHC==7.8.*, GHC==7.6.*, GHC==7.4.*, GHC==7.2.*, GHC==7.0.*
 
 extra-source-files:
     changelog.md
@@ -20,7 +20,7 @@
     location: http://git.haskell.org/packages/stm.git
 
 library
-    default-language: Haskell98
+    default-language: Haskell2010
     other-extensions:
         CPP
         DeriveDataTypeable
@@ -34,7 +34,7 @@
         other-extensions: Safe
 
     build-depends:
-        base  >= 4.2 && < 4.9,
+        base  >= 4.3 && < 4.10,
         array >= 0.3 && < 0.6
 
     exposed-modules: