diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c
index c7472eff2d514b475579d1a3e5a89269d04fce0e..b2ca095cb9dab36a4eb6e8da7308c4e55a6437cc 100644
--- a/net/ipv4/igmp.c
+++ b/net/ipv4/igmp.c
@@ -1716,7 +1716,8 @@ static int ip_mc_add_src(struct in_device *in_dev, __be32 *pmca, int sfmode,
 	if (err) {
 		int j;
 
-		pmc->sfcount[sfmode]--;
+		if (!delta)
+			pmc->sfcount[sfmode]--;
 		for (j=0; j<i; j++)
 			(void) ip_mc_del1_src(pmc, sfmode, &psfsrc[j]);
 	} else if (isexclude != (pmc->sfcount[MCAST_EXCLUDE] != 0)) {