diff --git a/ghc/lib/posix/PosixDB.lhs b/ghc/lib/posix/PosixDB.lhs
index 3ae82e42c6e1a343377e1ead206908dbbfd39e8c..2e9181cf63f51060ef001b829cb77b403989fb34 100644
--- a/ghc/lib/posix/PosixDB.lhs
+++ b/ghc/lib/posix/PosixDB.lhs
@@ -48,7 +48,7 @@ getGroupEntryForID :: GroupID -> IO GroupEntry
 getGroupEntryForID gid = do
     ptr <- _ccall_ getgrgid gid
     if ptr == nullAddr then
-	fail (IOError Nothing NoSuchThing
+	ioError (IOError Nothing NoSuchThing
 	     "getGroupEntryForID" "no such group entry")
      else
 	unpackGroupEntry ptr
@@ -58,7 +58,7 @@ getGroupEntryForName name = do
     gname <- packStringIO name
     ptr <- _ccall_ getgrnam gname
     if ptr == nullAddr then
-	fail (IOError Nothing NoSuchThing
+	ioError (IOError Nothing NoSuchThing
 	     "getGroupEntryForName" "no such group entry")
      else
 	unpackGroupEntry ptr
@@ -67,7 +67,7 @@ getUserEntryForID :: UserID -> IO UserEntry
 getUserEntryForID uid = do
     ptr <- _ccall_ getpwuid uid
     if ptr == nullAddr then
-	fail (IOError Nothing NoSuchThing
+	ioError (IOError Nothing NoSuchThing
 	     "getUserEntryForID" "no such user entry")
      else
 	unpackUserEntry ptr
@@ -77,7 +77,7 @@ getUserEntryForName name = do
     uname <- packStringIO name
     ptr   <- _ccall_ getpwnam uname
     if ptr == nullAddr then
-	fail (IOError Nothing NoSuchThing
+	ioError (IOError Nothing NoSuchThing
 	     "getUserEntryForName" "no such user entry")
      else
 	unpackUserEntry ptr
diff --git a/ghc/lib/posix/PosixFiles.lhs b/ghc/lib/posix/PosixFiles.lhs
index 5ca22b54ead5ae2c5dc8c1a07f48efbcd2a3cb7d..9795733f5559274a879247918facdc8a62cec89e 100644
--- a/ghc/lib/posix/PosixFiles.lhs
+++ b/ghc/lib/posix/PosixFiles.lhs
@@ -130,7 +130,7 @@ readDirStream dirp = do
        else do
 	     errno <- getErrorCode
 	     if errno == noError
-		then fail (IOError Nothing EOF "readDirStream" "EOF")
+		then ioError (IOError Nothing EOF "readDirStream" "EOF")
 		else syserr "readDirStream"
 
 rewindDirStream :: DirStream -> IO ()
@@ -141,7 +141,7 @@ rewindDirStream dirp = do
 closeDirStream :: DirStream -> IO ()
 closeDirStream dirp = do
     rc <- _ccall_ closedir dirp
-    if rc == 0
+    if rc == (0::Int)
        then return ()
        else syserr "closeDirStream"
 
@@ -275,7 +275,7 @@ openFd :: FilePath
 openFd name how maybe_mode (OpenFileFlags append exclusive noctty nonBlock truncate) =
     packStringIO name >>= \file ->
     _ccall_ open file flags mode_w >>= \fd@(I# fd#) ->
-    if fd /= -1
+    if fd /= ((-1)::Int)
        then return (FD# fd#)
        else syserr "openFd"
   where
@@ -310,7 +310,7 @@ createFile :: FilePath -> FileMode -> IO Fd
 createFile name mode =
     packStringIO name >>= \file ->
     _ccall_ creat file mode >>= \fd@(I# fd#) ->
-    if fd /= -1
+    if fd /= ((-1)::Int)
        then return (FD# fd#)
        else syserr "createFile"
 
@@ -322,7 +322,7 @@ createLink name1 name2 = do
     path1 <- packStringIO name1
     path2 <- packStringIO name2
     rc <- _ccall_ link path1 path2
-    if rc == 0
+    if rc == (0::Int)
        then return ()
        else syserr "createLink"
 
@@ -330,7 +330,7 @@ createDirectory :: FilePath -> FileMode -> IO ()
 createDirectory name mode = do -- NB: diff signature from LibDirectory one!
     dir <- packStringIO name
     rc  <- _ccall_ mkdir dir mode
-    if rc == 0
+    if rc == (0::Int)
        then return ()
        else syserr "createDirectory"
 
@@ -338,7 +338,7 @@ createNamedPipe :: FilePath -> FileMode -> IO ()
 createNamedPipe name mode = do
     pipe <- packStringIO name
     rc   <-_ccall_ mkfifo pipe mode
-    if rc == 0
+    if rc == (0::Int)
        then return ()
        else syserr "createNamedPipe"
 
@@ -346,7 +346,7 @@ removeLink :: FilePath -> IO ()
 removeLink name = do
     path <- packStringIO name
     rc   <-_ccall_ unlink path
-    if rc == 0
+    if rc == (0::Int)
        then return ()
        else syserr "removeLink"
 
@@ -355,7 +355,7 @@ rename name1 name2 = do
     path1 <- packStringIO name1
     path2 <- packStringIO name2
     rc    <- _ccall_ rename path1 path2
-    if rc == 0
+    if rc == (0::Int)
        then return ()
        else syserr "rename"
 
@@ -406,34 +406,34 @@ statusChangeTime stat = unsafePerformIO $
 isDirectory :: FileStatus -> Bool
 isDirectory stat = unsafePerformIO $
     _casm_ ``%r = S_ISDIR(((struct stat *)%0)->st_mode);'' stat >>= \ rc ->
-    return (rc /= 0)
+    return (rc /= (0::Int))
 
 isCharacterDevice :: FileStatus -> Bool
 isCharacterDevice stat = unsafePerformIO $
     _casm_ ``%r = S_ISCHR(((struct stat *)%0)->st_mode);'' stat >>= \ rc ->
-    return (rc /= 0)
+    return (rc /= (0::Int))
 
 isBlockDevice :: FileStatus -> Bool
 isBlockDevice stat = unsafePerformIO $
     _casm_ ``%r = S_ISBLK(((struct stat *)%0)->st_mode);'' stat >>= \ rc ->
-    return (rc /= 0)
+    return (rc /= (0::Int))
 
 isRegularFile :: FileStatus -> Bool
 isRegularFile stat = unsafePerformIO $
     _casm_ ``%r = S_ISREG(((struct stat *)%0)->st_mode);'' stat >>= \ rc ->
-    return (rc /= 0)
+    return (rc /= (0::Int))
 
 isNamedPipe :: FileStatus -> Bool
 isNamedPipe stat = unsafePerformIO $
     _casm_ ``%r = S_ISFIFO(((struct stat *)%0)->st_mode);'' stat >>= \ rc ->
-    return (rc /= 0)
+    return (rc /= (0::Int))
 
 getFileStatus :: FilePath -> IO FileStatus
 getFileStatus name = do
     path  <- packStringIO name
     bytes <- allocChars ``sizeof(struct stat)''
     rc    <- _casm_ ``%r = stat(%0,(struct stat *)%1);'' path bytes
-    if rc == 0
+    if rc == (0::Int)
        then do
 	    stat <- freeze bytes
 	    return stat
@@ -443,7 +443,7 @@ getFdStatus :: Fd -> IO FileStatus
 getFdStatus fd = do
     bytes <- allocChars ``sizeof(struct stat)''
     rc    <- _casm_ ``%r = fstat(%0,(struct stat *)%1);'' fd bytes
-    if rc == 0
+    if rc == (0::Int)
        then do
 	    stat <- freeze bytes
 	    return stat
@@ -453,7 +453,7 @@ fileAccess :: FilePath -> Bool -> Bool -> Bool -> IO Bool
 fileAccess name read write exec = do
     path <- packStringIO name
     rc   <- _ccall_ access path flags
-    return (rc == 0)
+    return (rc == (0::Int))
   where
     flags  = I# (word2Int# (read# `or#` write# `or#` exec#))
     read#  = case (if read  then ``R_OK'' else ``0'') of { W# x -> x }
@@ -464,13 +464,13 @@ fileExist :: FilePath -> IO Bool
 fileExist name = do
     path <- packStringIO name
     rc   <- _ccall_ access path (``F_OK''::Int)
-    return (rc == 0)
+    return (rc == (0::Int))
 
 setFileMode :: FilePath -> FileMode -> IO ()
 setFileMode name mode = do
     path <- packStringIO name
     rc   <- _ccall_ chmod path mode
-    if rc == 0
+    if rc == (0::Int)
        then return ()
        else syserr "setFileMode"
 
@@ -478,7 +478,7 @@ setOwnerAndGroup :: FilePath -> UserID -> GroupID -> IO ()
 setOwnerAndGroup name uid gid = do
     path <- packStringIO name
     rc   <- _ccall_ chown path uid gid
-    if rc == 0
+    if rc == (0::Int)
        then return ()
        else syserr "setOwnerAndGroup"
 
@@ -488,7 +488,7 @@ setFileTimes name atime mtime = do
     rc   <- _casm_ ``do {struct utimbuf ub; ub.actime = (time_t) %0;
 		         ub.modtime = (time_t) %1;
 		         %r = utime(%2, &ub);} while(0);'' atime mtime path
-    if rc == 0
+    if rc == (0::Int)
        then return ()
        else syserr "setFileTimes"
 
@@ -497,7 +497,7 @@ touchFile :: FilePath -> IO ()
 touchFile name = do
     path <- packStringIO name
     rc   <- _ccall_ utime path nullAddr
-    if rc == 0
+    if rc == (0::Int)
        then return ()
        else syserr "touchFile"
 
@@ -526,12 +526,12 @@ pathconf :: Int -> FilePath -> IO Limit
 pathconf n name = do
   path <- packStringIO name
   rc   <- _ccall_ pathconf path n
-  if rc /= -1
+  if rc /= ((-1)::Int)
      then return rc
      else do
 	  errno <-  getErrorCode
 	  if errno == invalidArgument
-	     then fail (IOError Nothing NoSuchThing "getPathVar" "no such path limit or option")
+	     then ioError (IOError Nothing NoSuchThing "getPathVar" "no such path limit or option")
 	     else syserr "PosixFiles.getPathVar"
 
 
@@ -550,12 +550,12 @@ getFileVar v fd =
 fpathconf :: Int -> Fd -> IO Limit
 fpathconf n fd = do
  rc <- _ccall_ fpathconf fd n
- if rc /= -1
+ if rc /= ((-1)::Int)
     then return rc
     else do
 	 errno <-  getErrorCode
 	 if errno == invalidArgument
-	    then fail (IOError Nothing NoSuchThing "getFileVar" "no such path limit or option")
+	    then ioError (IOError Nothing NoSuchThing "getFileVar" "no such path limit or option")
 	    else syserr "getFileVar"
 
 \end{code}
diff --git a/ghc/lib/posix/PosixIO.lhs b/ghc/lib/posix/PosixIO.lhs
index ff60aa865bf1d2420e5413c9d07def4e73a20a7c..fa527856a7da8443f03fde3dc62b4cb7e0eb9233 100644
--- a/ghc/lib/posix/PosixIO.lhs
+++ b/ghc/lib/posix/PosixIO.lhs
@@ -47,7 +47,7 @@ createPipe :: IO (Fd, Fd)
 createPipe = do
     bytes <- allocChars ``(2*sizeof(int))''
     rc    <- _casm_ ``%r = pipe((int *)%0);'' bytes
-    if rc /= -1
+    if rc /= ((-1)::Int)
        then do
 	rd <- _casm_ ``%r = ((int *)%0)[0];'' bytes
 	wd <- _casm_ ``%r = ((int *)%0)[1];'' bytes
@@ -79,8 +79,8 @@ handleToFd h = do
 fdToHandle :: Fd -> IO Handle
 fdToHandle fd@(FD# fd#) = do
      -- first find out what kind of file desc. this is..
-    flags <- _ccall_ fcntl fd (``F_GETFL''::Int) 0
-    if flags /= -1 
+    flags <- _ccall_ fcntl fd (``F_GETFL''::Int) (0::Int)
+    if flags /= ((-1)::Int)
      then do
       let
        (I# flags#) = flags
@@ -98,7 +98,7 @@ fdToHandle fd@(FD# fd#) = do
 	 | rwH       = (ReadWriteHandle, 1)
 	 | otherwise = (ReadHandle, 0)
 	  
-      fo <- _ccall_ openFd fd flags flush_on_close
+      fo <- _ccall_ openFd fd flags (flush_on_close::Int)
       if fo /= nullAddr then do
 	 {-
 	   A distinction is made here between std{Input,Output,Error} Fds
@@ -134,7 +134,7 @@ fdRead fd nbytes = do
     rc    <-  _ccall_ read fd bytes nbytes
     case rc of
       -1 -> syserr "fdRead"
-      0  -> fail (IOError Nothing EOF "fdRead" "EOF")
+      0  -> ioError (IOError Nothing EOF "fdRead" "EOF")
       n | n == nbytes -> do
 	    buf <- freeze bytes
 	    s   <- unpackNBytesBAIO buf n
@@ -153,7 +153,7 @@ fdWrite :: Fd -> String -> IO ByteCount
 fdWrite fd str = do
     buf <- packStringIO str
     rc  <- _ccall_ write fd buf (length str)
-    if rc /= -1
+    if rc /= ((-1)::Int)
        then return rc
        else syserr "fdWrite"
 
@@ -163,7 +163,7 @@ data FdOption = AppendOnWrite
 
 queryFdOption :: Fd -> FdOption -> IO Bool
 queryFdOption fd CloseOnExec =
-    _ccall_ fcntl fd (``F_GETFD''::Int) 0	    >>= \ (I# flags#) ->
+    _ccall_ fcntl fd (``F_GETFD''::Int) (0::Int)    >>= \ (I# flags#) ->
     if flags# /=# -1# then
 	return ((int2Word# flags# `and#` fd_cloexec#) `neWord#` int2Word# 0#)
     else
@@ -171,7 +171,7 @@ queryFdOption fd CloseOnExec =
   where
     fd_cloexec# = case (``FD_CLOEXEC'') of { W# x -> x }
 queryFdOption fd other =
-    _ccall_ fcntl fd (``F_GETFL''::Int) 0	    >>= \ (I# flags#) ->
+    _ccall_ fcntl fd (``F_GETFL''::Int) (0::Int)    >>= \ (I# flags#) ->
     if flags# >=# 0# then
 	return ((int2Word# flags# `and#` opt#) `neWord#` int2Word# 0#)
     else
@@ -184,13 +184,13 @@ queryFdOption fd other =
 
 setFdOption :: Fd -> FdOption -> Bool -> IO ()
 setFdOption fd CloseOnExec val = do
-    flags <- _ccall_ fcntl fd (``F_GETFD''::Int) 0
-    if flags /= -1 then do
+    flags <- _ccall_ fcntl fd (``F_GETFD''::Int) (0::Int)
+    if flags /= ((-1)::Int) then do
 	rc <- (if val then
 		 _casm_ ``%r = fcntl(%0, F_SETFD, %1 | FD_CLOEXEC);'' fd flags
 	       else do
 		 _casm_ ``%r = fcntl(%0, F_SETFD, %1 & ~FD_CLOEXEC);'' fd flags)
-	if rc /= -1
+	if rc /= ((-1)::Int)
 	   then return ()
 	   else fail
      else fail
@@ -198,13 +198,13 @@ setFdOption fd CloseOnExec val = do
     fail = syserr "setFdOption"
 
 setFdOption fd other val = do
-    flags <- _ccall_ fcntl fd (``F_GETFL''::Int) 0
-    if flags >= 0 then do
+    flags <- _ccall_ fcntl fd (``F_GETFL''::Int) (0::Int)
+    if flags >= (0::Int) then do
 	rc <- (if val then
 	         _casm_ ``%r = fcntl(%0, F_SETFL, %1 | %2);'' fd flags opt
 	       else do
 	         _casm_ ``%r = fcntl(%0, F_SETFL, %1 & ~(%2));'' fd flags opt)
-	if rc /= -1
+	if rc /= ((-1)::Int)
 	   then return ()
 	   else fail
      else fail
@@ -225,7 +225,7 @@ getLock :: Fd -> FileLock -> IO (Maybe (ProcessID, FileLock))
 getLock fd lock = do
     flock <- lock2Bytes lock
     rc    <- _ccall_ fcntl fd (``F_GETLK''::Int) flock
-    if rc /= -1
+    if rc /= ((-1)::Int)
        then do
 	    result <- bytes2ProcessIDAndLock flock
 	    return (maybeResult result)
@@ -247,7 +247,7 @@ waitToSetLock fd lock = do
 fdSeek :: Fd -> SeekMode -> FileOffset -> IO FileOffset
 fdSeek fd mode offset = do
     rc <- _ccall_ lseek fd offset (mode2Int mode)
-    if rc /= -1
+    if rc /= ((-1)::Int)
        then return rc
        else syserr "fdSeek"
 
diff --git a/ghc/lib/posix/PosixProcEnv.lhs b/ghc/lib/posix/PosixProcEnv.lhs
index c7bf7680677100f0e8cdf989de4c5838f599a06f..7d33f0ea84978bba7d6cd100be5440c85ab15188 100644
--- a/ghc/lib/posix/PosixProcEnv.lhs
+++ b/ghc/lib/posix/PosixProcEnv.lhs
@@ -99,10 +99,10 @@ setGroupID gid = nonzero_error (_ccall_ setgid gid) "setGroupID"
 #if !defined(cygwin32_TARGET_OS)
 getGroups :: IO [GroupID]
 getGroups = do
-    ngroups <- _ccall_ getgroups 0 nullAddr
+    ngroups <- _ccall_ getgroups (0::Int) nullAddr
     words   <- allocWords ngroups
     ngroups <- _casm_ ``%r = getgroups(%0,(gid_t *)%1);'' ngroups words
-    if ngroups /= -1
+    if ngroups /= ((-1)::Int)
        then do
 	 arr <- freeze words
          return (map (extract arr) [0..(ngroups-1)])
@@ -134,14 +134,14 @@ getProcessGroupID = _ccall_ getpgrp
 
 createProcessGroup :: ProcessID -> IO ProcessGroupID
 createProcessGroup pid = do
-    pgid <- _ccall_ setpgid pid 0
-    if pgid == 0
+    pgid <- _ccall_ setpgid pid (0::Int)
+    if pgid == (0::Int)
        then return pgid
        else syserr "createProcessGroup"
 
 joinProcessGroup :: ProcessGroupID -> IO ()
 joinProcessGroup pgid =
-    nonzero_error (_ccall_ setpgid 0 pgid) "joinProcessGroupID"
+    nonzero_error (_ccall_ setpgid (0::Int) pgid) "joinProcessGroupID"
 
 setProcessGroupID :: ProcessID -> ProcessGroupID -> IO ()
 setProcessGroupID pid pgid =
@@ -150,7 +150,7 @@ setProcessGroupID pid pgid =
 createSession :: IO ProcessGroupID
 createSession = do
     pgid <- _ccall_ setsid
-    if pgid /= -1
+    if pgid /= ((-1)::Int)
        then return pgid
        else syserr "createSession"
 
@@ -185,14 +185,14 @@ getSystemID :: IO SystemID
 getSystemID = do
     bytes <- allocChars (``sizeof(struct utsname)''::Int)
     rc    <- _casm_ ``%r = uname((struct utsname *)%0);'' bytes
-    if rc /= -1
+    if rc /= ((-1)::Int)
        then freeze bytes
        else syserr "getSystemID"
 
 epochTime :: IO EpochTime
 epochTime = do
     secs <- _ccall_ time nullAddr
-    if secs /= -1
+    if secs /= ((-1)::Int)
        then return secs
        else syserr "epochTime"
 
@@ -223,7 +223,7 @@ getProcessTimes :: IO ProcessTimes
 getProcessTimes = do
     bytes <- allocChars (``sizeof(struct tms)''::Int)
     elapsed <- _casm_ ``%r = times((struct tms *)%0);'' bytes
-    if elapsed /= -1
+    if elapsed /= ((-1)::Int)
        then do
 	    times <- freeze bytes
 	    return (elapsed, times)
@@ -235,7 +235,7 @@ getControllingTerminalName :: IO FilePath
 getControllingTerminalName = do
     str <- _ccall_ ctermid nullAddr
     if str == nullAddr
-       then fail (IOError Nothing NoSuchThing "getControllingTerminalName" "no controlling terminal")
+       then ioError (IOError Nothing NoSuchThing "getControllingTerminalName" "no controlling terminal")
        else strcpy str
 #endif
 
@@ -246,17 +246,17 @@ getTerminalName fd = do
        then do
         err <- try (queryTerminal fd)
         either (\err -> syserr "getTerminalName")
-               (\succ -> if succ then fail (IOError Nothing NoSuchThing
-					    "getTerminalName" "no name")
-                         else fail (IOError Nothing InappropriateType
-					    "getTerminalName" "not a terminal"))
+               (\succ -> if succ then ioError (IOError Nothing NoSuchThing
+						"getTerminalName" "no name")
+                         else ioError (IOError Nothing InappropriateType
+						"getTerminalName" "not a terminal"))
            err
        else strcpy str
 
 queryTerminal :: Fd -> IO Bool
 queryTerminal (FD# fd) = do
     rc <- _ccall_ isatty fd
-    case rc of
+    case (rc::Int) of
       -1 -> syserr "queryTerminal"
       0  -> return False
       1  -> return True
@@ -286,10 +286,10 @@ getSysVar v =
 sysconf :: Int -> IO Limit
 sysconf n = do
  rc <- _ccall_ sysconf n
- if rc /= -1
+ if rc /= (-1::Int)
     then return rc
-    else fail (IOError Nothing NoSuchThing
-		       "getSysVar" 
-		       "no such system limit or option")
+    else ioError (IOError Nothing NoSuchThing
+		          "getSysVar" 
+		          "no such system limit or option")
 
 \end{code}
diff --git a/ghc/lib/posix/PosixProcPrim.lhs b/ghc/lib/posix/PosixProcPrim.lhs
index b6272af6a0cc7dac2619a3704c142baa4a120f53..7e93a2111badec479de4f37d61ace082d3794f2c 100644
--- a/ghc/lib/posix/PosixProcPrim.lhs
+++ b/ghc/lib/posix/PosixProcPrim.lhs
@@ -114,7 +114,7 @@ import PosixProcEnv (getProcessID)
 forkProcess :: IO (Maybe ProcessID)
 forkProcess = do
     pid <-_ccall_ fork
-    case pid of
+    case (pid::Int) of
       -1 -> syserr "forkProcess"
       0  -> return Nothing
       _  -> return (Just pid)
@@ -155,7 +155,7 @@ getProcessStatus block stopped pid = do
     wstat <- allocWords 1
     pid   <-_casm_ ``%r = waitpid(%0, (int *)%1, %2);'' pid wstat
 		(waitOptions block stopped)
-    case pid of
+    case (pid::Int) of
       -1 -> syserr "getProcessStatus"
       0  -> return Nothing
       _  -> do ps <- decipherWaitStatus wstat
@@ -169,7 +169,7 @@ getGroupProcessStatus block stopped pgid = do
     wstat <- allocWords 1
     pid   <-_casm_ ``%r = waitpid(%0, (int *)%1, %2);'' (-pgid) wstat
 		   (waitOptions block stopped)
-    case pid of
+    case (pid::Int) of
       -1 -> syserr "getGroupProcessStatus"
       0  -> return Nothing
       _  -> do ps <- decipherWaitStatus wstat
@@ -215,8 +215,7 @@ getEnvVar name = do
     str <- packStringIO name
     str <- _ccall_ getenv str
     if str == nullAddr
-       then fail (IOError Nothing NoSuchThing
-		 "getEnvVar" "no such environment variable")
+       then ioError (IOError Nothing NoSuchThing "getEnvVar" "no such environment variable")
        else strcpy str
 
 setEnvVar :: String -> String -> IO ()
@@ -324,15 +323,15 @@ signalProcessGroup int pgid = signalProcess int (-pgid)
 
 setStoppedChildFlag :: Bool -> IO Bool
 setStoppedChildFlag b = do
-    rc <- _casm_ ``%r = nocldstop; nocldstop = %0;'' x
-    return (rc == 0)
+    rc <- _casm_ ``%r = nocldstop; nocldstop = %0;'' (x::Int)
+    return (rc == (0::Int))
   where
     x = case b of {True -> 0; False -> 1}
 
 queryStoppedChildFlag :: IO Bool
 queryStoppedChildFlag = do
     rc <- _casm_ ``%r = nocldstop;''
-    return (rc == 0)
+    return (rc == (0::Int))
 
 data Handler = Default
              | Ignore
@@ -364,7 +363,7 @@ addSignal int oldset = unsafePerformPrimIO $ do
 inSignalSet :: Signal -> SignalSet -> Bool
 inSignalSet int sigset = unsafePerformPrimIO $ do
     rc <- _casm_ ``%r = sigismember((sigset_t *)%0, %1);'' sigset int
-    return (rc == 1)
+    return (rc == (1::Int))
 
 deleteSignal :: Signal -> SignalSet -> SignalSet
 deleteSignal int oldset = unsafePerformPrimIO $ do
@@ -378,7 +377,7 @@ installHandler :: Signal
                -> IO Handler		-- old handler
 
 #ifdef __PARALLEL_HASKELL__
-installHandler = fail (userError "installHandler: not available for Parallel Haskell")
+installHandler = ioError (userError "installHandler: not available for Parallel Haskell")
 #else
 installHandler int handler maybe_mask = (
     case handler of
@@ -389,7 +388,7 @@ installHandler int handler maybe_mask = (
 	_ccall_ stg_sig_catch int sptr mask
     ) >>= \rc ->
 
-    if rc >= 0 then do
+    if rc >= (0::Int) then do
         osptr <- _casm_ ``%r = (StgStablePtr) (%0);'' rc
         m     <- deRefStablePtr osptr
 	return (Catch m)
@@ -410,7 +409,7 @@ getSignalMask :: IO SignalSet
 getSignalMask = do
     bytes <- allocChars sigSetSize
     rc    <- _casm_ ``%r = sigprocmask(0, NULL, (sigset_t *)%0);'' bytes
-    if rc == 0
+    if rc == (0::Int)
        then freeze bytes
        else syserr "getSignalMask"
 
@@ -419,7 +418,7 @@ sigProcMask name how sigset = do
     bytes <- allocChars sigSetSize
     rc <- _casm_ ``%r = sigprocmask(%0, (sigset_t *)%1, (sigset_t *)%2);''
 		 how sigset bytes
-    if rc == 0
+    if rc == (0::Int)
        then freeze bytes
        else syserr name
 
@@ -436,7 +435,7 @@ getPendingSignals :: IO SignalSet
 getPendingSignals = do
     bytes <- allocChars sigSetSize
     rc <- _casm_ ``%r = sigpending((sigset_t *)%0);'' bytes
-    if rc == 0
+    if rc == (0::Int)
        then freeze bytes
        else syserr "getPendingSignals"
 
@@ -494,15 +493,15 @@ waitOptions True  True  = ``WUNTRACED''
 decipherWaitStatus :: MutableByteArray s x -> IO ProcessStatus
 decipherWaitStatus wstat = do
     exited <- _casm_ ``%r = WIFEXITED(*(int *)%0);'' wstat
-    if exited /= 0
+    if exited /= (0::Int)
       then do
         exitstatus <- _casm_ ``%r = WEXITSTATUS(*(int *)%0);'' wstat
-        if exitstatus == 0
+        if exitstatus == (0::Int)
 	   then return (Exited ExitSuccess)
 	   else return (Exited (ExitFailure exitstatus))
       else do
         signalled <- _casm_ ``%r = WIFSIGNALED(*(int *)%0);'' wstat
-        if signalled /= 0
+        if signalled /= (0::Int)
 	   then do
 		termsig <- _casm_ ``%r = WTERMSIG(*(int *)%0);'' wstat
 		return (Terminated termsig)
diff --git a/ghc/lib/posix/PosixTTY.lhs b/ghc/lib/posix/PosixTTY.lhs
index 80c9eb140392137f347e50565b7f0b8191ac559d..555f917e39010932e5e7539b7b661376c2777fcf 100644
--- a/ghc/lib/posix/PosixTTY.lhs
+++ b/ghc/lib/posix/PosixTTY.lhs
@@ -223,7 +223,7 @@ controlChar :: TerminalAttributes -> ControlCharacter -> Maybe Char
 controlChar termios cc = unsafePerformIO $ do
     val <- _casm_ ``%r = ((struct termios *)%0)->c_cc[%1];''
 		  termios (cc2Word cc)
-    if val == ``_POSIX_VDISABLE''
+    if val == (``_POSIX_VDISABLE''::Int)
        then return Nothing
        else return (Just (toEnum val))
 
@@ -314,7 +314,7 @@ getTerminalAttributes :: Fd -> IO TerminalAttributes
 getTerminalAttributes (FD# fd) = do
     bytes <- allocChars ``sizeof(struct termios)''
     rc <- _casm_ ``%r = tcgetattr(%0,(struct termios *)%1);'' fd bytes
-    if rc /= -1
+    if rc /= ((-1)::Int)
        then freeze bytes
        else syserr "getTerminalAttributes"
 
@@ -329,7 +329,7 @@ setTerminalAttributes :: Fd
 setTerminalAttributes (FD# fd) termios state = do
     rc <- _casm_ ``%r = tcsetattr(%0,%1,(struct termios *)%2);''
 		 fd (state2Int state) termios
-    if rc /= -1
+    if rc /= ((-1)::Int)
        then return ()
        else syserr "setTerminalAttributes"
   where
@@ -377,7 +377,7 @@ controlFlow (FD# fd) action =
 getTerminalProcessGroupID :: Fd -> IO ProcessGroupID
 getTerminalProcessGroupID (FD# fd) = do
     pgid <- _ccall_ tcgetpgrp fd
-    if pgid /= -1
+    if pgid /= ((-1)::Int)
        then return pgid
        else syserr "getTerminalProcessGroupID"
 
diff --git a/ghc/lib/posix/PosixUtil.lhs b/ghc/lib/posix/PosixUtil.lhs
index 19cc3389fbeb06d0d2c140692b2c7f4f144ff2fd..b02cb251723ef6f7bc685fa0037afed99d6f3ceb 100644
--- a/ghc/lib/posix/PosixUtil.lhs
+++ b/ghc/lib/posix/PosixUtil.lhs
@@ -49,10 +49,10 @@ errno.
 
 \begin{code}
 syserr :: String -> IO a
-syserr str = fail (IOError Nothing     -- ToDo: better
-			   SystemError
-			   str
-			   "")
+syserr str = ioError (IOError Nothing     -- ToDo: better
+			      SystemError
+			      str
+			      "")
 
 -- common templates for system calls