diff --git a/System/Posix/IO/Common.hsc b/System/Posix/IO/Common.hsc
index eb4a721199c848e0c2ff7d7ee809a8329761dd78..abcd19b2b9c1c5665dbf41530de0b3a2e06a280d 100644
--- a/System/Posix/IO/Common.hsc
+++ b/System/Posix/IO/Common.hsc
@@ -79,11 +79,6 @@ import GHC.IO.Exception
 import Data.Typeable (cast)
 #endif
 
-#ifdef __HUGS__
-import Hugs.Prelude (IOException(..), IOErrorType(..))
-import qualified Hugs.IO (handleToFd, openFd)
-#endif
-
 #include "HsUnix.h"
 
 -- -----------------------------------------------------------------------------
@@ -239,16 +234,6 @@ handleToFd' h h_@Handle__{haType=_,..} = do
 fdToHandle fd = FD.fdToHandle (fromIntegral fd)
 #endif
 
-#ifdef __HUGS__
-handleToFd h = do
-  fd <- Hugs.IO.handleToFd h
-  return (fromIntegral fd)
-
-fdToHandle fd = do
-  mode <- fdGetMode (fromIntegral fd)
-  Hugs.IO.openFd (fromIntegral fd) False mode True
-#endif
-
 -- -----------------------------------------------------------------------------
 -- Fd options
 
diff --git a/System/Posix/Process.hsc b/System/Posix/Process.hsc
index 42426a3585222fa9f4ab5f132349c84f785df643..72da1c6d8c15a442e71630b684471608508b754b 100644
--- a/System/Posix/Process.hsc
+++ b/System/Posix/Process.hsc
@@ -78,10 +78,6 @@ import System.Posix.Process.Internals
 import System.Posix.Process.Common
 import System.Posix.Internals ( withFilePath )
 
-#ifdef __HUGS__
-{-# CFILES cbits/HsUnix.c  #-}
-#endif
-
 -- | @'executeFile' cmd args env@ calls one of the
 --   @execv*@ family, depending on whether or not the current
 --   PATH is to be searched for the command, and whether or not an
diff --git a/System/Posix/Process/ByteString.hsc b/System/Posix/Process/ByteString.hsc
index ee2c9cf364d8f5902f00999a0b489ecd21dfe6e3..64fc71ee6c23418a31163114c42dee42bba57737 100644
--- a/System/Posix/Process/ByteString.hsc
+++ b/System/Posix/Process/ByteString.hsc
@@ -90,10 +90,6 @@ import qualified Data.ByteString.Char8 as BC
 
 import System.Posix.ByteString.FilePath
 
-#ifdef __HUGS__
-{-# CFILES cbits/HsUnix.c  #-}
-#endif
-
 -- | @'executeFile' cmd args env@ calls one of the
 --   @execv*@ family, depending on whether or not the current
 --   PATH is to be searched for the command, and whether or not an
diff --git a/System/Posix/Process/Common.hsc b/System/Posix/Process/Common.hsc
index ee7310eb8f7c3deb42eb392657fecaf6671e1864..d0d2b093390d908f57424ee39cf0652ef2dde59b 100644
--- a/System/Posix/Process/Common.hsc
+++ b/System/Posix/Process/Common.hsc
@@ -88,10 +88,6 @@ import GHC.TopHandler   ( runIO )
 import GHC.IO ( unsafeUnmask, uninterruptibleMask_ )
 #endif
 
-#ifdef __HUGS__
-{-# CFILES cbits/HsUnix.c  #-}
-#endif
-
 -- -----------------------------------------------------------------------------
 -- Process environment
 
diff --git a/System/Posix/Signals.hsc b/System/Posix/Signals.hsc
index 9119190927b99a37a4832858bd862de16f597b6b..e8fc1c50da7c13da9a3fc392b173f67e55aeafd0 100644
--- a/System/Posix/Signals.hsc
+++ b/System/Posix/Signals.hsc
@@ -602,16 +602,7 @@ awaitSignal maybe_sigset = do
 foreign import ccall unsafe "sigsuspend"
   c_sigsuspend :: Ptr CSigset -> IO CInt
 
-#ifdef __HUGS__
-foreign import ccall unsafe "sigdelset"
-  c_sigdelset   :: Ptr CSigset -> CInt -> IO CInt
-
-foreign import ccall unsafe "sigfillset"
-  c_sigfillset  :: Ptr CSigset -> IO CInt
-
-foreign import ccall unsafe "sigismember"
-  c_sigismember :: Ptr CSigset -> CInt -> IO CInt
-#elif defined(darwin_HOST_OS) && __GLASGOW_HASKELL__ < 706
+#if defined(darwin_HOST_OS) && __GLASGOW_HASKELL__ < 706
 -- see http://ghc.haskell.org/trac/ghc/ticket/7359#comment:3
 -- To be removed when support for GHC 7.4.x is dropped
 foreign import ccall unsafe "__hscore_sigdelset"
@@ -631,7 +622,7 @@ foreign import capi unsafe "signal.h sigfillset"
 
 foreign import capi unsafe "signal.h sigismember"
   c_sigismember :: Ptr CSigset -> CInt -> IO CInt
-#endif /* __HUGS__ */
+#endif
 
 foreign import ccall unsafe "sigpending"
   c_sigpending :: Ptr CSigset -> IO CInt
diff --git a/System/Posix/Temp.hsc b/System/Posix/Temp.hsc
index 349030b0a7cd9148c433ce310834974383235a7c..2d7ca52c048275afaa1ad403bb28d5c87414d070 100644
--- a/System/Posix/Temp.hsc
+++ b/System/Posix/Temp.hsc
@@ -33,7 +33,7 @@ import System.Posix.IO
 import System.Posix.Types
 import System.Posix.Internals (withFilePath, peekFilePath)
 
-#if defined(__GLASGOW_HASKELL__) || defined(__HUGS__)
+#if defined(__GLASGOW_HASKELL__)
 foreign import ccall unsafe "HsUnix.h __hscore_mkstemp"
   c_mkstemp :: CString -> IO CInt
 #endif
@@ -48,7 +48,7 @@ foreign import ccall unsafe "HsUnix.h __hscore_mkstemp"
 mkstemp :: String -> IO (FilePath, Handle)
 mkstemp template' = do
   let template = template' ++ "XXXXXX"
-#if defined(__GLASGOW_HASKELL__) || defined(__HUGS__)
+#if defined(__GLASGOW_HASKELL__)
   withFilePath template $ \ ptr -> do
     fd <- throwErrnoIfMinus1 "mkstemp" (c_mkstemp ptr)
     name <- peekFilePath ptr
@@ -114,7 +114,7 @@ mkdtemp template' = do
   return name
 #endif
 
-#if (!defined(__GLASGOW_HASKELL__) && !defined(__HUGS__)) || !HAVE_MKDTEMP
+#if !defined(__GLASGOW_HASKELL__) || !HAVE_MKDTEMP
 
 foreign import ccall unsafe "mktemp"
   c_mktemp :: CString -> IO CString
diff --git a/System/Posix/Temp/ByteString.hsc b/System/Posix/Temp/ByteString.hsc
index 61bd7e9acbcd26cff6b76bfed8545ab09d4cdb5b..84ad49ed4f740c57748d98a909e88c2ef9ca5c93 100644
--- a/System/Posix/Temp/ByteString.hsc
+++ b/System/Posix/Temp/ByteString.hsc
@@ -38,7 +38,7 @@ import System.Posix.Directory (createDirectory)
 import System.Posix.IO
 import System.Posix.Types
 
-#if defined(__GLASGOW_HASKELL__) || defined(__HUGS__)
+#if defined(__GLASGOW_HASKELL__)
 foreign import ccall unsafe "HsUnix.h __hscore_mkstemp"
   c_mkstemp :: CString -> IO CInt
 #endif
@@ -53,7 +53,7 @@ foreign import ccall unsafe "HsUnix.h __hscore_mkstemp"
 mkstemp :: ByteString -> IO (RawFilePath, Handle)
 mkstemp template' = do
   let template = template' `B.append` (BC.pack "XXXXXX")
-#if defined(__GLASGOW_HASKELL__) || defined(__HUGS__)
+#if defined(__GLASGOW_HASKELL__)
   withFilePath template $ \ ptr -> do
     fd <- throwErrnoIfMinus1 "mkstemp" (c_mkstemp ptr)
     name <- peekFilePath ptr
@@ -114,7 +114,7 @@ mkdtemp template' = do
   return name
 #endif
 
-#if (!defined(__GLASGOW_HASKELL__) && !defined(__HUGS__)) || !HAVE_MKDTEMP
+#if !defined(__GLASGOW_HASKELL__) || !HAVE_MKDTEMP
 
 foreign import ccall unsafe "mktemp"
   c_mktemp :: CString -> IO CString