diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index d507b54..1ab0b91 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -13,8 +13,8 @@ jobs:
         ghc:
           - 8.8.4
           - 8.10.7
-          - 9.0.1
-          - 9.2.1
+          - 9.0.2
+          - 9.2.4
       fail-fast: false
     continue-on-error: ${{ startsWith(matrix.os, 'windows') && startsWith(matrix.ghc, '9.2') }}
     
diff --git a/.gitignore b/.gitignore
index a5f630a..26cfce9 100644
--- a/.gitignore
+++ b/.gitignore
@@ -4,3 +4,4 @@
 *.swp
 .ghc.*
 .stack-work
+cabal.project.local
diff --git a/cabal.project b/cabal.project
new file mode 100644
index 0000000..6a6840c
--- /dev/null
+++ b/cabal.project
@@ -0,0 +1 @@
+packages: ./unix-compat.cabal
diff --git a/src/System/PosixCompat/Types.hs b/src/System/PosixCompat/Types.hs
index f9288bc..82fcbb9 100644
--- a/src/System/PosixCompat/Types.hs
+++ b/src/System/PosixCompat/Types.hs
@@ -1,47 +1,163 @@
 {-# LANGUAGE CPP #-}
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
 
+{-# OPTIONS_GHC -Wno-unused-imports #-}
+
 {-|
 This module re-exports the types from @System.Posix.Types@ on all platforms.
-
-On Windows 'UserID', 'GroupID' and 'LinkCount' are missing, so they are
-redefined by this module.
+It defines drop-in replacements for types that are missing from that module on a
+specific OS. Namely Mac OS and Windows are supported.
 -}
 module System.PosixCompat.Types (
       module System.Posix.Types
+#ifdef darwin_HOST_OS
+    , CTimer(..)
+#endif
 #ifdef mingw32_HOST_OS
+    , CBlkCnt(..)
+    , CBlkSize(..)
+    , CCc(..)
+    , CFsBlkCnt(..)
+    , CFsFilCnt(..)
+    , CId(..)
+    , CKey(..)
+    , CRLim(..)
+    , CSpeed(..)
+    , CTcflag(..)
+    , CTimer(..)
     , UserID
+    , CUid(..)
     , GroupID
+    , CGid(..)
     , LinkCount
+    , CNlink(..)
+#endif
+#if defined mingw32_HOST_OS || !MIN_VERSION_base(4, 14, 0)
+    , CNfds(..)
+    , CSocklen(..)
 #endif
     ) where
 
+import Data.Int (Int32, Int64)
+import Data.Word (Word8, Word32, Word64)
+import Foreign (Ptr)
+import System.Posix.Types
+
+#ifdef darwin_HOST_OS
+
+newtype CTimer = CTimer (Ptr ())
+  deriving (Eq, Ord)
+instance Show CTimer where show (CTimer x) = show x
+
+#endif
+
 #ifdef mingw32_HOST_OS
 -- Since CIno (FileID's underlying type) reflects <sys/type.h> ino_t,
 -- which mingw defines as short int (int16), it must be overriden to
 -- match the size of windows fileIndex (word64).
-import System.Posix.Types
 
-import Data.Word (Word32)
+newtype CBlkCnt = CBlkCnt Int64
+  deriving (Eq, Ord, Enum, Bounded, Integral, Num, Real)
+instance Show CBlkCnt where show (CBlkCnt x) = show x
+instance Read CBlkCnt where readsPrec i s = [ (CBlkCnt x, s')
+                                          | (x,s') <- readsPrec i s]
 
-newtype UserID = UserID Word32
+newtype CBlkSize = CBlkSize Int64
   deriving (Eq, Ord, Enum, Bounded, Integral, Num, Real)
-instance Show UserID where show (UserID x) = show x
-instance Read UserID where readsPrec i s = [ (UserID x, s')
+instance Show CBlkSize where show (CBlkSize x) = show x
+instance Read CBlkSize where readsPrec i s = [ (CBlkSize x, s')
                                            | (x,s') <- readsPrec i s]
 
-newtype GroupID = GroupID Word32
+newtype CCc = CCc Word8
+  deriving (Eq, Ord, Enum, Bounded, Integral, Num, Real)
+instance Show CCc where show (CCc x) = show x
+instance Read CCc where readsPrec i s = [ (CCc x, s')
+                                      | (x,s') <- readsPrec i s]
+
+newtype CFsBlkCnt = CFsBlkCnt Word64
   deriving (Eq, Ord, Enum, Bounded, Integral, Num, Real)
-instance Show GroupID where show (GroupID x) = show x
-instance Read GroupID where readsPrec i s = [ (GroupID x, s')
+instance Show CFsBlkCnt where show (CFsBlkCnt x) = show x
+instance Read CFsBlkCnt where readsPrec i s = [ (CFsBlkCnt x, s')
                                             | (x,s') <- readsPrec i s]
 
-newtype LinkCount = LinkCount Word32
+newtype CFsFilCnt = CFsFilCnt Word64
   deriving (Eq, Ord, Enum, Bounded, Integral, Num, Real)
-instance Show LinkCount where show (LinkCount x) = show x
-instance Read LinkCount where readsPrec i s = [ (LinkCount x, s')
-                                              | (x,s') <- readsPrec i s]
+instance Show CFsFilCnt where show (CFsFilCnt x) = show x
+instance Read CFsFilCnt where readsPrec i s = [ (CFsFilCnt x, s')
+                                            | (x,s') <- readsPrec i s]
+
+newtype CId = CId Word32
+  deriving (Eq, Ord, Enum, Bounded, Integral, Num, Real)
+instance Show CId where show (CId x) = show x
+instance Read CId where readsPrec i s = [ (CId x, s')
+                                      | (x,s') <- readsPrec i s]
+
+newtype CKey = CKey Int32
+  deriving (Eq, Ord, Enum, Bounded, Integral, Num, Real)
+instance Show CKey where show (CKey x) = show x
+instance Read CKey where readsPrec i s = [ (CKey x, s')
+                                       | (x,s') <- readsPrec i s]
+
+newtype CRLim = CRLim Word64
+  deriving (Eq, Ord, Enum, Bounded, Integral, Num, Real)
+instance Show CRLim where show (CRLim x) = show x
+instance Read CRLim where readsPrec i s = [ (CRLim x, s')
+                                        | (x,s') <- readsPrec i s]
+
+newtype CSpeed = CSpeed Word32
+  deriving (Eq, Ord, Enum, Bounded, Integral, Num, Real)
+instance Show CSpeed where show (CSpeed x) = show x
+instance Read CSpeed where readsPrec i s = [ (CSpeed x, s')
+                                        | (x,s') <- readsPrec i s]
+
+newtype CTcflag = CTcflag Word32
+  deriving (Eq, Ord, Enum, Bounded, Integral, Num, Real)
+instance Show CTcflag where show (CTcflag x) = show x
+instance Read CTcflag where readsPrec i s = [ (CTcflag x, s')
+                                        | (x,s') <- readsPrec i s]
+
+newtype CTimer = CTimer (Ptr ())
+  deriving (Eq, Ord)
+instance Show CTimer where show (CTimer x) = show x
+
+type UserID = CUid
+
+newtype CUid = CUid Word32
+  deriving (Eq, Ord, Enum, Bounded, Integral, Num, Real)
+instance Show CUid where show (CUid x) = show x
+instance Read CUid where readsPrec i s = [ (CUid x, s')
+                                         | (x,s') <- readsPrec i s]
+
+type GroupID = CGid
+
+newtype CGid = CGid Word32
+  deriving (Eq, Ord, Enum, Bounded, Integral, Num, Real)
+instance Show CGid where show (CGid x) = show x
+instance Read CGid where readsPrec i s = [ (CGid x, s')
+                                         | (x,s') <- readsPrec i s]
+
+type LinkCount = CNlink
+
+newtype CNlink = CNlink Word64
+  deriving (Eq, Ord, Enum, Bounded, Integral, Num, Real)
+instance Show CNlink where show (CNlink x) = show x
+instance Read CNlink where readsPrec i s = [ (CNlink x, s')
+                                           | (x,s') <- readsPrec i s]
+
+#endif
+
+#if defined mingw32_HOST_OS || !MIN_VERSION_base(4, 14, 0)
+
+newtype CNfds = CNfds Word64
+  deriving (Eq, Ord, Enum, Bounded, Integral, Num, Real)
+instance Show CNfds where show (CNfds x) = show x
+instance Read CNfds where readsPrec i s = [ (CNfds x, s')
+                                          | (x,s') <- readsPrec i s]
+
+newtype CSocklen = CSocklen Word32
+  deriving (Eq, Ord, Enum, Bounded, Integral, Num, Real)
+instance Show CSocklen where show (CSocklen x) = show x
+instance Read CSocklen where readsPrec i s = [ (CSocklen x, s')
+                                             | (x,s') <- readsPrec i s]
 
-#else
-import System.Posix.Types
 #endif
diff --git a/tests/check-types.hs b/tests/check-types.hs
new file mode 100644
index 0000000..3505046
--- /dev/null
+++ b/tests/check-types.hs
@@ -0,0 +1,178 @@
+{-# LANGUAGE CPP #-}
+
+{-# OPTIONS_GHC -Wno-unused-top-binds #-}
+
+module Main (main) where
+
+import Data.Int
+import Data.Word
+import System.PosixCompat.Types
+
+import qualified Foreign
+import qualified Foreign.C.Types
+
+main :: IO ()
+main = pure ()
+
+newtypeCBlkCnt :: CBlkCnt -> Int64
+newtypeCBlkCnt (CBlkCnt x) = x
+
+#ifdef darwin_HOST_OS
+newtypeCBlkSize :: CBlkSize -> Int32
+#else
+newtypeCBlkSize :: CBlkSize -> Int64
+#endif
+newtypeCBlkSize (CBlkSize x) = x
+
+newtypeCCc :: CCc -> Word8
+newtypeCCc (CCc x) = x
+
+#ifdef darwin_HOST_OS
+newtypeCClockId :: CClockId -> Word32
+#else
+newtypeCClockId :: CClockId -> Int32
+#endif
+newtypeCClockId (CClockId x) = x
+
+#ifdef darwin_HOST_OS
+newtypeCDev :: CDev -> Int32
+#elif defined mingw32_HOST_OS
+newtypeCDev :: CDev -> Word32
+#else
+newtypeCDev :: CDev -> Word64
+#endif
+newtypeCDev (CDev x) = x
+
+#ifdef darwin_HOST_OS
+newtypeCFsBlkCnt :: CFsBlkCnt -> Word32
+#else
+newtypeCFsBlkCnt :: CFsBlkCnt -> Word64
+#endif
+newtypeCFsBlkCnt (CFsBlkCnt x) = x
+
+#ifdef darwin_HOST_OS
+newtypeCFsFilCnt :: CFsFilCnt -> Word32
+#else
+newtypeCFsFilCnt :: CFsFilCnt -> Word64
+#endif
+newtypeCFsFilCnt (CFsFilCnt x) = x
+
+newtypeCGid :: CGid -> Word32
+newtypeCGid (CGid x) = x
+
+newtypeCId :: CId -> Word32
+newtypeCId (CId x) = x
+
+#ifdef mingw32_HOST_OS
+newtypeCIno :: CIno -> Word16
+#else
+newtypeCIno :: CIno -> Word64
+#endif
+newtypeCIno (CIno x) = x
+
+newtypeCKey :: CKey -> Int32
+newtypeCKey (CKey x) = x
+
+#ifdef darwin_HOST_OS
+newtypeCMode :: CMode -> Word16
+#elif defined mingw32_HOST_OS
+newtypeCMode :: CMode -> Word16
+#else
+newtypeCMode :: CMode -> Word32
+#endif
+newtypeCMode (CMode x) = x
+
+#if defined darwin_HOST_OS && MIN_VERSION_base(4, 14, 0)
+newtypeCNfds :: CNfds -> Word32
+#else
+newtypeCNfds :: CNfds -> Word64
+#endif
+newtypeCNfds (CNfds x) = x
+
+#ifdef darwin_HOST_OS
+newtypeCNlink :: CNlink -> Word16
+#else
+newtypeCNlink :: CNlink -> Word64
+#endif
+newtypeCNlink (CNlink x) = x
+
+newtypeCOff :: COff -> Int64
+newtypeCOff (COff x) = x
+
+#ifdef mingw32_HOST_OS
+newtypeCPid :: CPid -> Int64
+#else
+newtypeCPid :: CPid -> Int32
+#endif
+newtypeCPid (CPid x) = x
+
+newtypeCRLim :: CRLim -> Word64
+newtypeCRLim (CRLim x) = x
+
+newtypeCSocklen :: CSocklen -> Word32
+newtypeCSocklen (CSocklen x) = x
+
+#ifdef darwin_HOST_OS
+newtypeCSpeed :: CSpeed -> Word64
+#else
+newtypeCSpeed :: CSpeed -> Word32
+#endif
+newtypeCSpeed (CSpeed x) = x
+
+newtypeCSsize :: CSsize -> Int64
+newtypeCSsize (CSsize x) = x
+
+#ifdef darwin_HOST_OS
+newtypeCTcflag :: CTcflag -> Word64
+#else
+newtypeCTcflag :: CTcflag -> Word32
+#endif
+newtypeCTcflag (CTcflag x) = x
+
+newtypeCTimer :: CTimer -> Foreign.Ptr ()
+newtypeCTimer (CTimer x) = x
+
+newtypeCUid :: CUid -> Word32
+newtypeCUid (CUid x) = x
+
+newtypeFd :: Fd -> Foreign.C.Types.CInt
+newtypeFd (Fd x) = x
+
+typeByteCount :: ByteCount -> Foreign.C.Types.CSize
+typeByteCount = id
+
+typeClockTick :: ClockTick -> Foreign.C.Types.CClock
+typeClockTick = id
+
+typeDeviceID :: DeviceID -> CDev
+typeDeviceID = id
+
+typeEpochTime :: EpochTime -> Foreign.C.Types.CTime
+typeEpochTime = id
+
+typeFileID :: FileID -> CIno
+typeFileID = id
+
+typeFileMode :: FileMode -> CMode
+typeFileMode = id
+
+typeFileOffset :: FileOffset -> COff
+typeFileOffset = id
+
+typeGroupID :: GroupID -> CGid
+typeGroupID = id
+
+typeLimit :: Limit -> Foreign.C.Types.CLong
+typeLimit = id
+
+typeLinkCount :: LinkCount -> CNlink
+typeLinkCount = id
+
+typeProcessGroupID :: ProcessGroupID -> CPid
+typeProcessGroupID = id
+
+typeProcessID :: ProcessID -> CPid
+typeProcessID = id
+
+typeUserID :: UserID -> CUid
+typeUserID = id
diff --git a/unix-compat.cabal b/unix-compat.cabal
index 8879404..94eb267 100644
--- a/unix-compat.cabal
+++ b/unix-compat.cabal
@@ -146,3 +146,15 @@ Test-Suite unix-compat-testsuite
       cc-options: -DSOLARIS
 
     build-depends: directory >= 1.3.1 && < 1.4
+
+Test-Suite unix-compat-check-types
+  default-language: Haskell2010
+  type: exitcode-stdio-1.0
+  hs-source-dirs: tests
+  ghc-options: -Wall
+  main-is: check-types.hs
+
+  build-depends:
+      unix-compat
+    , base == 4.*
+