diff --git a/package/swconfig/src/swlib.c b/package/swconfig/src/swlib.c
index 531a23a1ab..de08717e33 100644
--- a/package/swconfig/src/swlib.c
+++ b/package/swconfig/src/swlib.c
@@ -38,7 +38,7 @@
 static struct nl_sock *handle;
 static struct nl_cache *cache;
 static struct genl_family *family;
-static struct nlattr *tb[SWITCH_ATTR_MAX];
+static struct nlattr *tb[SWITCH_ATTR_MAX + 1];
 static int refcount = 0;
 
 static struct nla_policy port_policy[] = {