Index: channels/chan_sip.c
===================================================================
--- channels/chan_sip.c	(revision 423)
+++ channels/chan_sip.c	(revision 424)
@@ -29973,6 +29973,17 @@
 		ast_string_field_set(p, todnid, dnid);
 	}
 
+	if (ast_strlen_zero(tmp)) {
+		*cause = AST_CAUSE_DESTINATION_OUT_OF_ORDER;
+		ast_debug(3, "Cant create SIP call - destination not specified\n");
+		dialog_unlink_all(p);
+		dialog_unref(p, "unref dialog p destination not specified");
+		if (callid) {
+			ast_callid_unref(callid);
+		}
+		return NULL;
+	}
+
 	/* Divvy up the items separated by slashes */
 	AST_NONSTANDARD_APP_ARGS(args, tmp, '/');