diff --git a/lib/msg.c b/lib/msg.c
index dafee67..6478507 100644
--- a/lib/msg.c
+++ b/lib/msg.c
@@ -886,10 +886,10 @@ static void dump_attrs(FILE *ofd, struct nlattr *attrs, int attrlen,
 			fprintf(ofd, "  [ATTR PADDING] %d octets\n", alen);
 		else
 			fprintf(ofd, "  [ATTR %02d%s] %d octets\n", nla_type(nla),
-				nla->nla_type & NLA_F_NESTED ? " NESTED" : "",
+				nla_is_nested(nla) ? " NESTED" : "",
 				alen);
 
-		if (nla->nla_type & NLA_F_NESTED)
+		if (nla_is_nested(nla))
 			dump_attrs(ofd, nla_data(nla), alen, prefix+1);
 		else
 			dump_attr(ofd, nla, prefix);
diff --git a/lib/socket.c b/lib/socket.c
index d3e636e..1ca7783 100644
--- a/lib/socket.c
+++ b/lib/socket.c
@@ -120,7 +120,7 @@ static struct nl_sock *__alloc_socket(struct nl_cb *cb)
 		return NULL;
 
 	sk->s_fd = -1;
-	sk->s_cb = cb;
+	sk->s_cb = nl_cb_get(cb);
 	sk->s_local.nl_family = AF_NETLINK;
 	sk->s_peer.nl_family = AF_NETLINK;
 	sk->s_seq_expect = sk->s_seq_next = time(0);
@@ -141,12 +141,18 @@ static struct nl_sock *__alloc_socket(struct nl_cb *cb)
 struct nl_sock *nl_socket_alloc(void)
 {
 	struct nl_cb *cb;
-	
+        struct nl_sock *sk;
+
 	cb = nl_cb_alloc(default_cb);
 	if (!cb)
 		return NULL;
 
-	return __alloc_socket(cb);
+        /* will increment cb reference count on success */
+	sk = __alloc_socket(cb);
+
+        nl_cb_put(cb);
+
+        return sk;
 }
 
 /**
@@ -163,7 +169,7 @@ struct nl_sock *nl_socket_alloc_cb(struct nl_cb *cb)
 	if (cb == NULL)
 		BUG();
 
-	return __alloc_socket(nl_cb_get(cb));
+	return __alloc_socket(cb);
 }
 
 /**
@@ -519,6 +525,9 @@ struct nl_cb *nl_socket_get_cb(const struct nl_sock *sk)
 
 void nl_socket_set_cb(struct nl_sock *sk, struct nl_cb *cb)
 {
+        if (cb == NULL)
+                BUG();
+
 	nl_cb_put(sk->s_cb);
 	sk->s_cb = nl_cb_get(cb);
 }