diff --git a/pjlib/include/pj/sock.h b/pjlib/include/pj/sock.h
index a6e760aa9..7321c5de8 100644
--- a/pjlib/include/pj/sock.h
+++ b/pjlib/include/pj/sock.h
@@ -102,15 +102,12 @@ extern const pj_uint16_t PJ_SO_RCVBUF;  /**< Buffer size for receive.   */
 extern const pj_uint16_t PJ_SO_SNDBUF;  /**< Buffer size for send.      */
 
 
-/**
+/*
  * Flags to be specified in #pj_sock_recv, #pj_sock_send, etc.
  */
-typedef enum pj_sock_msg_flag
-{
-    PJ_MSG_OOB		= 0x01,	    /**< Out-of-band messages.		 */
-    PJ_MSG_PEEK		= 0x02,	    /**< Peek, don't remove from buffer. */
-    PJ_MSG_DONTROUTE	= 0x04	    /**< Don't route.			 */
-} pj_sock_msg_flag;
+extern const int PJ_MSG_OOB;	    /**< Out-of-band messages.		 */
+extern const int PJ_MSG_PEEK;	    /**< Peek, don't remove from buffer. */
+extern const int PJ_MSG_DONTROUTE;  /**< Don't route.			 */
 
 
 /**
diff --git a/pjlib/src/pj/sock_bsd.c b/pjlib/src/pj/sock_bsd.c
index 49fe0232d..617453080 100644
--- a/pjlib/src/pj/sock_bsd.c
+++ b/pjlib/src/pj/sock_bsd.c
@@ -82,6 +82,12 @@ const pj_uint16_t PJ_SO_RCVBUF  = SO_RCVBUF;
 const pj_uint16_t PJ_SO_SNDBUF  = SO_SNDBUF;
 
 
+/* recv() and send() flags */
+const int PJ_MSG_OOB		= MSG_OOB;
+const int PJ_MSG_PEEK		= MSG_PEEK;
+const int PJ_MSG_DONTROUTE	= MSG_DONTROUTE;
+
+
 #if defined(PJ_SOCKADDR_HAS_LEN) && PJ_SOCKADDR_HAS_LEN!=0
 #   define SET_LEN(addr,len) (((pj_sockaddr*)(addr))->sa_zero_len=(len))
 #   define RESET_LEN(addr)   (((pj_sockaddr*)(addr))->sa_zero_len=0)