diff -Nur asterisk-16.6.2-org/res/res_pjsip_messaging.c asterisk-16.6.2/res/res_pjsip_messaging.c
--- asterisk-16.6.2-org/res/res_pjsip_messaging.c	2019-11-21 22:14:58.000000000 +0100
+++ asterisk-16.6.2/res/res_pjsip_messaging.c	2020-01-17 03:54:17.467358407 +0100
@@ -745,7 +745,7 @@
 		return PJ_FALSE;
 	}
 
-	code = check_content_type(rdata);
+	code = check_content_type_in_dialog(rdata);
 	if (code != PJSIP_SC_OK) {
 		send_response(rdata, code, NULL, NULL);
 		return PJ_TRUE;