diff --git a/sendfile.cabal b/sendfile.cabal
--- a/sendfile.cabal
+++ b/sendfile.cabal
@@ -1,5 +1,5 @@
 name:          sendfile
-version:       0.7.3
+version:       0.7.4
 stability:     provisional
 synopsis:      A portable sendfile library
 description:   A library which exposes zero-copy sendfile functionality in a portable way. If a platform does not support sendfile, a fallback implementation in haskell is provided.
diff --git a/src/Network/Socket/SendFile/Darwin.hsc b/src/Network/Socket/SendFile/Darwin.hsc
--- a/src/Network/Socket/SendFile/Darwin.hsc
+++ b/src/Network/Socket/SendFile/Darwin.hsc
@@ -10,6 +10,7 @@
 import Foreign.Storable (peek, poke)
 import Network.Socket.SendFile.Iter (Iter(..), runIter)
 import System.Posix.Types (Fd)
+#include <stdio.h>
 
 _sendFile :: Fd -> Fd -> Int64 -> Int64 -> IO ()
 _sendFile out_fd in_fd off count = 
diff --git a/src/Network/Socket/SendFile/Linux.hsc b/src/Network/Socket/SendFile/Linux.hsc
--- a/src/Network/Socket/SendFile/Linux.hsc
+++ b/src/Network/Socket/SendFile/Linux.hsc
@@ -2,7 +2,7 @@
 -- | Linux system-dependent code for 'sendfile'.
 module Network.Socket.SendFile.Linux (_sendFile, sendFileIter, sendfile) where
 
-import Data.Int (Int32, Int64)
+import Data.Int (Int32, Int64)    -- Int64 is imported on 64-bit systems
 import Data.Word (Word32, Word64) -- Word64 is imported on 64-bit systems
 import Foreign.C.Error (eAGAIN, getErrno, throwErrno)
 import Foreign.Marshal (alloca)
@@ -66,7 +66,7 @@
                 else throwErrno "Network.Socket.SendFile.Linux.sendfileI"
       else return (False, fromIntegral sbytes)
 
-safeMinus :: (Ord a, Num a) => a -> a -> a
+safeMinus :: (Ord a, Num a, Show a) => a -> a -> a
 safeMinus x y
     | y > x = error $ "y > x " ++ show (y,x)
     | otherwise = x - y