diff --git a/Network/Socket/ByteString/IO.hsc b/Network/Socket/ByteString/IO.hsc
index 83442548..382a40c2 100644
--- a/Network/Socket/ByteString/IO.hsc
+++ b/Network/Socket/ByteString/IO.hsc
@@ -95,9 +95,10 @@ sendAll :: Socket     -- ^ Connected socket
         -> IO ()
 sendAll _ "" = return ()
 sendAll s bs = do
+    -- "send" throws an exception.
     sent <- send s bs
     waitWhen0 sent s
-    when (sent >= 0) $ sendAll s $ B.drop sent bs
+    when (sent /= B.length bs) $ sendAll s $ B.drop sent bs
 
 -- | Send data to the socket.  The recipient can be specified
 -- explicitly, so the socket need not be in a connected state.
diff --git a/Network/Socket/ByteString/Lazy/Posix.hs b/Network/Socket/ByteString/Lazy/Posix.hs
index 5d799bea..cf08825a 100644
--- a/Network/Socket/ByteString/Lazy/Posix.hs
+++ b/Network/Socket/ByteString/Lazy/Posix.hs
@@ -52,6 +52,7 @@ sendAll
     -> IO ()
 sendAll _ "" = return ()
 sendAll s bs = do
+    -- "send" throws an exception.
     sent <- send s bs
     waitWhen0 (fromIntegral sent) s
-    when (sent >= 0) $ sendAll s $ L.drop sent bs
+    when (sent /= L.length bs) $ sendAll s $ L.drop sent bs
diff --git a/Network/Socket/ByteString/Lazy/Windows.hs b/Network/Socket/ByteString/Lazy/Windows.hs
index a703c67c..d96bf5cc 100644
--- a/Network/Socket/ByteString/Lazy/Windows.hs
+++ b/Network/Socket/ByteString/Lazy/Windows.hs
@@ -30,6 +30,7 @@ sendAll
     -> IO ()
 sendAll _ "" = return ()
 sendAll s bs = do
+    -- "send" throws an exception.
     sent <- send s bs
     waitWhen0 (fromIntegral sent) s
-    when (sent >= 0) $ sendAll s $ L.drop sent bs
+    when (sent /= L.length bs) $ sendAll s $ L.drop sent bs