diff --git a/lib/Makefile.in b/lib/Makefile.in
index 1ef72b31..af9be59b 100644
--- a/lib/Makefile.in
+++ b/lib/Makefile.in
@@ -229,7 +229,7 @@ dist_libwebsockets_la_SOURCES = libwebsockets.c handshake.c parsers.c \
 libwebsockets_la_CFLAGS := -rdynamic -fPIC -Wall -Werror -std=gnu99 -pedantic -c \
 	-DDATADIR=\"@datadir@\" -DLWS_OPENSSL_CLIENT_CERTS=\"@clientcertdir@\"
 
-libwebsockets_la_LDFLAGS = -version-info 0:3
+libwebsockets_la_LDFLAGS = -lz -version-info 0:3
 all: all-am
 
 .SUFFIXES:
diff --git a/lib/libwebsockets.c b/lib/libwebsockets.c
index 72a3fe5e..2ce43fb0 100644
--- a/lib/libwebsockets.c
+++ b/lib/libwebsockets.c
@@ -582,10 +582,12 @@ user_service:
 		LWS_CALLBACK_CLEAR_MODE_POLL_FD,
 		(void *)(long)wsi->sock, NULL, POLLOUT);
 
-	wsi->protocol->callback(context, wsi,
-		LWS_CALLBACK_CLIENT_WRITEABLE,
-		wsi->user_space,
-		NULL, 0);
+	if (wsi->mode == LWS_CONNMODE_WS_CLIENT)
+		n = LWS_CALLBACK_CLIENT_WRITEABLE;
+	else
+		n = LWS_CALLBACK_SERVER_WRITEABLE;
+
+	wsi->protocol->callback(context, wsi, n, wsi->user_space, NULL, 0);
 
 	return 0;
 }
diff --git a/lib/libwebsockets.h b/lib/libwebsockets.h
index c3096c93..a8e635bd 100644
--- a/lib/libwebsockets.h
+++ b/lib/libwebsockets.h
@@ -55,6 +55,7 @@ enum libwebsocket_callback_reasons {
 	LWS_CALLBACK_CLIENT_RECEIVE,
 	LWS_CALLBACK_CLIENT_RECEIVE_PONG,
 	LWS_CALLBACK_CLIENT_WRITEABLE,
+	LWS_CALLBACK_SERVER_WRITEABLE,
 	LWS_CALLBACK_HTTP,
 	LWS_CALLBACK_BROADCAST,
 	LWS_CALLBACK_FILTER_NETWORK_CONNECTION,
@@ -244,12 +245,15 @@ struct libwebsocket_context;
  *				libwebsockets_serve_http_file() makes it very
  *				simple to send back a file to the client.
  *
- *	LWS_CALLBACK_CLIENT_WRITEABLE:  if you call
+ *	LWS_CALLBACK_CLIENT_WRITEABLE:
+ *      LWS_CALLBACK_SERVER_WRITEABLE:   If you call
  *		libwebsocket_callback_on_writable() on a connection, you will
- *		get this callback coming when the connection socket is able to
- *		accept another write packet without blocking.  If it already
- *		was able to take another packet without blocking, you'll get
- *		this callback at the next call to the service loop function.
+ *		get one of these callbacks coming when the connection socket
+ *		is able to accept another write packet without blocking.
+ *		If it already was able to take another packet without blocking,
+ *		you'll get this callback at the next call to the service loop
+ *		function.  Notice that CLIENTs get LWS_CALLBACK_CLIENT_WRITEABLE
+ *		and servers get LWS_CALLBACK_SERVER_WRITEABLE.
  *
  *	LWS_CALLBACK_FILTER_NETWORK_CONNECTION: called when a client connects to
  *		the server at network level; the connection is accepted but then
diff --git a/test-server/test-server-extpoll.c b/test-server/test-server-extpoll.c
index 3616f554..f2594d98 100644
--- a/test-server/test-server-extpoll.c
+++ b/test-server/test-server-extpoll.c
@@ -311,7 +311,7 @@ callback_lws_mirror(struct libwebsocket_context * this,
 		libwebsocket_callback_on_writable(this, wsi);
 		break;
 
-	case LWS_CALLBACK_CLIENT_WRITEABLE:
+	case LWS_CALLBACK_SERVER_WRITEABLE:
 
 		if (pss->ringbuffer_tail != ringbuffer_head) {
 
diff --git a/test-server/test-server.c b/test-server/test-server.c
index 7394645b..2cb063c3 100644
--- a/test-server/test-server.c
+++ b/test-server/test-server.c
@@ -270,7 +270,7 @@ callback_lws_mirror(struct libwebsocket_context * context,
 		pss->wsi = wsi;
 		break;
 
-	case LWS_CALLBACK_CLIENT_WRITEABLE:
+	case LWS_CALLBACK_SERVER_WRITEABLE:
 		if (close_testing)
 			break;
 		if (pss->ringbuffer_tail != ringbuffer_head) {