diff -rupN pjproject-2.5.5/pjlib/src/pj/ioqueue_common_abs.c pjproject-2.5.5-new/pjlib/src/pj/ioqueue_common_abs.c
--- pjproject-2.5.5/pjlib/src/pj/ioqueue_common_abs.c	2015-11-06 05:18:46.000000000 +0100
+++ pjproject-2.5.5-new/pjlib/src/pj/ioqueue_common_abs.c	2017-01-05 14:15:09.259518106 +0100
@@ -1047,7 +1047,8 @@ retry_on_restart:
     /*
      * Check that address storage can hold the address parameter.
      */
-    PJ_ASSERT_RETURN(addrlen <= (int)sizeof(pj_sockaddr_in), PJ_EBUG);
+    PJ_ASSERT_RETURN((((pj_sockaddr*)addr)->addr.sa_family == pj_AF_INET() && addrlen <= (int)sizeof(pj_sockaddr_in)) ||
+					 (((pj_sockaddr*)addr)->addr.sa_family == pj_AF_INET6() && addrlen <= (int)sizeof(pj_sockaddr_in6)), PJ_EBUG);
 
     /*
      * Schedule asynchronous send.
diff -rupN pjproject-2.5.5/pjlib/src/pj/ioqueue_common_abs.h pjproject-2.5.5-new/pjlib/src/pj/ioqueue_common_abs.h
--- pjproject-2.5.5/pjlib/src/pj/ioqueue_common_abs.h	2013-02-21 12:18:36.000000000 +0100
+++ pjproject-2.5.5-new/pjlib/src/pj/ioqueue_common_abs.h	2017-01-05 14:15:09.259518106 +0100
@@ -63,7 +63,7 @@ struct write_operation
     pj_size_t		    size;
     pj_ssize_t              written;
     unsigned                flags;
-    pj_sockaddr_in	    rmt_addr;
+    pj_sockaddr	    rmt_addr;
     int			    rmt_addrlen;
 };