diff --git a/channels/chan_zap.c b/channels/chan_zap.c
index 8932f0a4c0..dc8c44041c 100755
--- a/channels/chan_zap.c
+++ b/channels/chan_zap.c
@@ -1001,8 +1001,14 @@ static inline int zt_set_hook(int fd, int hs)
 
 static inline int zt_confmute(struct zt_pvt *p, int muted)
 {
-	int x, res;
+	int x, y, res;
 	x = muted;
+	if (p->sig == SIG_PRI) {
+		y = 1;
+		res = ioctl(p->subs[SUB_REAL].zfd, ZT_CONFMUTE, &x);
+		if (res)
+			ast_log(LOG_WARNING, "Unable to set audio mode on '%d'\n", p->channel);
+	}
 	res = ioctl(p->subs[SUB_REAL].zfd, ZT_CONFMUTE, &x);
 	if (res < 0) 
 		ast_log(LOG_WARNING, "zt confmute(%d) failed on channel %d: %s\n", muted, p->channel, strerror(errno));