diff --git a/addons/chan_ooh323.c b/addons/chan_ooh323.c
index bca7a8b96a..988778b313 100644
--- a/addons/chan_ooh323.c
+++ b/addons/chan_ooh323.c
@@ -4579,7 +4579,7 @@ struct ast_frame *ooh323_rtp_read(struct ast_channel *ast, struct ooh323_pvt *p)
 		f = &null_frame;
 	}
 
-	if (p->owner && !p->faxmode && (f->frametype == AST_FRAME_VOICE)) {
+	if (f && p->owner && !p->faxmode && (f->frametype == AST_FRAME_VOICE)) {
 		/* We already hold the channel lock */
 		if (!(ast_format_cap_iscompatible(p->owner->nativeformats, &f->subclass.format))) {
 			ast_debug(1, "Oooh, voice format changed to %s\n", ast_getformatname(&f->subclass.format));
diff --git a/channels/chan_h323.c b/channels/chan_h323.c
index 23952b7db6..5f28720865 100644
--- a/channels/chan_h323.c
+++ b/channels/chan_h323.c
@@ -772,7 +772,7 @@ static struct ast_frame *oh323_rtp_read(struct oh323_pvt *pvt)
 	if (f && (f->frametype == AST_FRAME_DTMF) && !(pvt->options.dtmfmode & (H323_DTMF_RFC2833 | H323_DTMF_CISCO))) {
 		return &ast_null_frame;
 	}
-	if (pvt->owner) {
+	if (f && pvt->owner) {
 		/* We already hold the channel lock */
 		if (f->frametype == AST_FRAME_VOICE) {
 			if (!ast_format_cap_iscompatible(pvt->owner->nativeformats, &f->subclass.format)) {