diff --git a/os/Xtrans.c b/os/Xtrans.c
index 9c9c851b7e..5dd8729543 100644
--- a/os/Xtrans.c
+++ b/os/Xtrans.c
@@ -117,13 +117,6 @@ Xtransport_table Xtransports[] = {
 
 #define NUMTRANS	(sizeof(Xtransports)/sizeof(Xtransport_table))
 
-
-#ifdef WIN32
-#define ioctl ioctlsocket
-#endif
-
-
-
 /*
  * These are a few utility function used by the public interface functions.
  */
@@ -564,7 +557,7 @@ int _XSERVTransNonBlock(XtransConnInfo ciptr)
 	{
 	    int arg;
 	    arg = 1;
-	    ret = ioctl (fd, FIOSNBIO, &arg);
+	    ret = ossock_ioctl (fd, FIOSNBIO, &arg);
 	}
 #else
 #if defined(WIN32)
@@ -572,7 +565,7 @@ int _XSERVTransNonBlock(XtransConnInfo ciptr)
 	    u_long arg_ret = 1;
 /* IBM TCP/IP understands this option too well: it causes _XSERVTransRead to fail
  * eventually with EWOULDBLOCK */
-	    ret = ioctl (fd, FIONBIO, &arg_ret);
+	    ret = ossock_ioctl (fd, FIONBIO, &arg_ret);
 	}
 #else
 	    ret = fcntl (fd, F_GETFL, 0);
diff --git a/os/Xtranssock.c b/os/Xtranssock.c
index b608630ddf..455356f1a3 100644
--- a/os/Xtranssock.c
+++ b/os/Xtranssock.c
@@ -74,6 +74,8 @@ from the copyright holders.
 #include <X11/Xthreads.h>
 #endif
 
+#include "os/ossock.h"
+
 #ifndef WIN32
 
 #if defined(TCPCONN) || defined(UNIXCONN)
@@ -1178,15 +1180,7 @@ static int _XSERVTransSocketBytesReadable (
 {
     prmsg (2,"SocketBytesReadable(%p,%d,%p)\n",
 	(void *) ciptr, ciptr->fd, (void *) pend);
-#ifdef WIN32
-    {
-	int ret = ioctlsocket ((SOCKET) ciptr->fd, FIONREAD, (u_long *) pend);
-	if (ret == SOCKET_ERROR) errno = WSAGetLastError();
-	return ret;
-    }
-#else
-    return ioctl (ciptr->fd, FIONREAD, (char *) pend);
-#endif /* WIN32 */
+    return ossock_ioctl (ciptr->fd, FIONREAD, pend);
 }
 
 #if XTRANS_SEND_FDS
diff --git a/os/ossock.c b/os/ossock.c
index 3100b63126..22dfaed2e3 100644
--- a/os/ossock.c
+++ b/os/ossock.c
@@ -6,6 +6,8 @@
 
 #ifdef WIN32
 #include <X11/Xwinsock.h>
+#else
+#include <sys/ioctl.h>
 #endif
 
 #include "os/ossock.h"
@@ -18,3 +20,15 @@ void ossock_init(void)
         WSAStartup(0x0202, &wsadata);
 #endif
 }
+
+int ossock_ioctl(int fd, unsigned long request, void *arg)
+{
+#ifdef WIN32
+    int ret = ioctlsocket(fd, request, arg);
+    if (ret == SOCKET_ERROR)
+        ret = WSAGetLastError();
+    return ret;
+#else
+    return ioctl(fd, request,arg);
+#endif
+}
diff --git a/os/ossock.h b/os/ossock.h
index c62575693b..1faeb0b545 100644
--- a/os/ossock.h
+++ b/os/ossock.h
@@ -5,9 +5,16 @@
 #ifndef _XSERVER_OS_OSSOCK_H_
 #define _XSERVER_OS_OSSOCK_H_
 
+#include <errno.h>
+
 /*
  * os specific initialization of the socket layer
  */
 void ossock_init(void);
 
+/*
+ * os specific socket ioctl function
+ */
+int ossock_ioctl(int fd, unsigned long request, void *arg);
+
 #endif /* _XSERVER_OS_OSSOCK_H_ */