diff --git a/Network/Wai/Handler/Warp/Counter.hs b/Network/Wai/Handler/Warp/Counter.hs
--- a/Network/Wai/Handler/Warp/Counter.hs
+++ b/Network/Wai/Handler/Warp/Counter.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE CPP #-}
 module Network.Wai.Handler.Warp.Counter (
     Counter
   , newCounter
@@ -6,6 +7,7 @@
   , decrease
   ) where
 
+#if USE_ATOMIC_PRIMOPS
 import qualified Data.Atomics.Counter.Unboxed as C
 import Control.Applicative ((<$>))
 
@@ -22,3 +24,22 @@
 
 decrease :: Counter -> IO ()
 decrease (Counter ref) = C.incrCounter_ (-1) ref
+#else
+
+import Network.Wai.Handler.Warp.IORef
+import Control.Applicative ((<$>))
+
+newtype Counter = Counter (IORef Int)
+
+newCounter :: IO Counter
+newCounter = Counter <$> newIORef 0
+
+isZero :: Counter -> IO Bool
+isZero (Counter ref) = (== 0) <$> readIORef ref
+
+increase :: Counter -> IO ()
+increase (Counter ref) = atomicModifyIORef' ref (\x -> (x + 1, ()))
+
+decrease :: Counter -> IO ()
+decrease (Counter ref) = atomicModifyIORef' ref (\x -> (x - 1, ()))
+#endif
diff --git a/Network/Wai/Handler/Warp/Timeout.hs b/Network/Wai/Handler/Warp/Timeout.hs
--- a/Network/Wai/Handler/Warp/Timeout.hs
+++ b/Network/Wai/Handler/Warp/Timeout.hs
@@ -59,7 +59,12 @@
 import System.Mem.Weak (deRefWeak)
 import Data.Typeable (Typeable)
 import Control.Reaper
+#if USE_ATOMIC_PRIMOPS
 import qualified Data.Atomics.Counter.Unboxed as C
+import Data.Atomics.Counter.Unboxed (casCounter)
+#else
+import Network.Wai.Handler.Warp.IORef
+#endif
 
 ----------------------------------------------------------------
 
@@ -70,7 +75,12 @@
 type TimeoutAction = IO ()
 
 -- | A handle used by 'Manager'
-data Handle = Handle TimeoutAction {-# UNPACK #-} !C.AtomicCounter
+data Handle = Handle TimeoutAction
+#if USE_ATOMIC_PRIMOPS
+    {-# UNPACK #-} !C.AtomicCounter
+#else
+    {-# UNPACK #-} !(IORef Int)
+#endif
 
 -- Four states for the AtomicCounter:
 --
@@ -91,7 +101,7 @@
   where
     prune m@(Handle onTimeout iactive) = do
         -- Try to change from active to inactive
-        (wasActive, newState) <- C.casCounter iactive 1 2
+        (wasActive, newState) <- casCounter iactive 1 2
         case newState of
             2 | not wasActive -> do -- inactive
                 onTimeout `E.catch` ignoreAll
@@ -99,6 +109,14 @@
             4 -> return Nothing -- canceled
             _        -> return $ Just m
 
+#if !USE_ATOMIC_PRIMOPS
+casCounter :: IORef Int -> Int -> Int -> IO (Bool, Int)
+casCounter ref old new = atomicModifyIORef' ref $ \curr ->
+    if old == curr
+        then (new, (True, new))
+        else (old, (False, old))
+#endif
+
 ----------------------------------------------------------------
 
 -- | Stopping timeout manager.
@@ -115,7 +133,11 @@
 -- | Registering a timeout action.
 register :: Manager -> TimeoutAction -> IO Handle
 register mgr onTimeout = do
+#if USE_ATOMIC_PRIMOPS
     iactive <- C.newCounter 1
+#else
+    iactive <- newIORef 1
+#endif
     let h = Handle onTimeout iactive
     reaperAdd mgr h
     return h
@@ -149,20 +171,28 @@
 
 ----------------------------------------------------------------
 
+writeCounter :: Int -> Handle -> IO ()
+#if USE_ATOMIC_PRIMOPS
+writeCounter i (Handle _ iactive) = C.writeCounter iactive i
+#else
+writeCounter i (Handle _ iactive) = writeIORef iactive i
+#endif
+{-# INLINE writeCounter #-}
+
 -- | Setting the state to active.
 --   'Manager' turns active to inactive repeatedly.
 tickle :: Handle -> IO ()
-tickle (Handle _ iactive) = C.writeCounter iactive 1
+tickle = writeCounter 1
 
 -- | Setting the state to canceled.
 --   'Manager' eventually removes this without timeout action.
 cancel :: Handle -> IO ()
-cancel (Handle _ iactive) = C.writeCounter iactive 4
+cancel = writeCounter 4
 
 -- | Setting the state to paused.
 --   'Manager' does not change the value.
 pause :: Handle -> IO ()
-pause (Handle _ iactive) = C.writeCounter iactive 3
+pause = writeCounter 3
 
 -- | Setting the paused state to active.
 --   This is an alias to 'tickle'.
diff --git a/warp.cabal b/warp.cabal
--- a/warp.cabal
+++ b/warp.cabal
@@ -1,5 +1,5 @@
 Name:                warp
-Version:             3.0.2.1
+Version:             3.0.2.2
 Synopsis:            A fast, light-weight web server for WAI applications.
 License:             MIT
 License-file:        LICENSE
@@ -52,7 +52,10 @@
                    , wai                       >= 3.0      && < 3.1
                    , text
                    , streaming-commons         >= 0.1.2
-                   , atomic-primops            >= 0.6
+
+  if impl(ghc >= 7.8)
+      Build-Depends: atomic-primops            >= 0.6
+      cpp-options:   -DUSE_ATOMIC_PRIMOPS
   if flag(network-bytestring)
       Build-Depends: network                   >= 2.2.1.5  && < 2.2.3
                    , network-bytestring        >= 0.1.3    && < 0.1.4
@@ -144,7 +147,10 @@
                    , text
                    , streaming-commons >= 0.1.1
                    , async
-                   , atomic-primops
+
+  if impl(ghc >= 7.8)
+      Build-Depends: atomic-primops            >= 0.6
+      cpp-options:   -DUSE_ATOMIC_PRIMOPS
 
   if (os(linux) || os(freebsd) || os(darwin)) && flag(allow-sendfilefd)
     Cpp-Options:   -DSENDFILEFD