diff --git a/ssl/d1_both.c b/ssl/d1_both.c
index 5bb0a4ff6ce1f02e2b54c0f4b638dee97ff5602a..ffc8ffe5d55d22887a93d7b8109bc8b7bfaf81d0 100644
--- a/ssl/d1_both.c
+++ b/ssl/d1_both.c
@@ -279,7 +279,7 @@ int dtls1_do_write(SSL *s, int type)
 			 * retransmit 
 			 */
 			if ( BIO_ctrl(SSL_get_wbio(s),
-				BIO_CTRL_DGRAM_MTU_EXCEEDED, 0, NULL))
+				BIO_CTRL_DGRAM_MTU_EXCEEDED, 0, NULL) > 0 )
 				s->d1->mtu = BIO_ctrl(SSL_get_wbio(s),
 					BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL);
 			else