diff --git a/src/Control/Monad/Base.hs b/src/Control/Monad/Base.hs
--- a/src/Control/Monad/Base.hs
+++ b/src/Control/Monad/Base.hs
@@ -13,8 +13,6 @@
 import Data.Monoid
 import Data.Functor.Identity
 import Control.Applicative (Applicative)
-import qualified Control.Monad.ST.Lazy as L
-import qualified Control.Monad.ST.Strict as S
 import Control.Monad.Trans.Class
 import Control.Monad.Trans.Identity
 import Control.Monad.Trans.Maybe
@@ -28,7 +26,15 @@
 import qualified Control.Monad.Trans.RWS.Strict as S
 import Control.Monad.Trans.Error
 import Control.Monad.Trans.Cont
+
+#if MIN_VERSION_base(4,4,0)
+import qualified Control.Monad.ST.Lazy as L
+import qualified Control.Monad.ST.Strict as S
+#endif
+
+#if MIN_VERSION_base(4,3,0)
 import GHC.Conc.Sync (STM)
+#endif
 
 class (Applicative b, Applicative m, Monad b, Monad m)
       ⇒ MonadBase b m | m → b where
@@ -39,14 +45,21 @@
 instance MonadBase (M) (M) where liftBase = id
 
 BASE(IO)
-BASE(L.ST s)
-BASE(S.ST s)
-BASE(STM)
 BASE(Maybe)
 BASE(Either e)
 BASE([])
 BASE((→) r)
 BASE(Identity)
+
+#if MIN_VERSION_base(4,3,0)
+BASE(STM)
+#endif
+
+#if MIN_VERSION_base(4,4,0)
+BASE(L.ST s)
+BASE(S.ST s)
+#endif
+
 #undef BASE
 
 -- | Can be used as a default implementation for 'liftBase'.
diff --git a/transformers-base.cabal b/transformers-base.cabal
--- a/transformers-base.cabal
+++ b/transformers-base.cabal
@@ -1,5 +1,5 @@
 Name: transformers-base
-Version: 0.4
+Version: 0.4.0.1
 Category: Control
 Stability: experimental
 Synopsis: Lift computations from the bottom of a transformer stack
@@ -29,7 +29,7 @@
 
 Library
   Build-Depends:
-    base          >= 4.4 && < 5,
+    base          >= 3 && < 5,
     transformers  >= 0.2
   Hs-Source-Dirs: src
   GHC-Options: -Wall