diff --git a/src/ipset.c b/src/ipset.c
index a34ed96..f175fa4 100644
--- a/src/ipset.c
+++ b/src/ipset.c
@@ -110,7 +110,7 @@ static int new_add_to_ipset(const char *setname, const struct all_addr *ipaddr,
       return -1;
     }
   
-  memset(buffer, 0, sizeof(buffer));
+  memset(buffer, 0, BUFF_SZ);
 
   nlh = (struct nlmsghdr *)buffer;
   nlh->nlmsg_len = NL_ALIGN(sizeof(struct nlmsghdr));