diff --git a/src/irc/core/netsplit.c b/src/irc/core/netsplit.c
index 865c9842..ded153ae 100644
--- a/src/irc/core/netsplit.c
+++ b/src/irc/core/netsplit.c
@@ -103,6 +103,8 @@ static NETSPLIT_REC *netsplit_add(IRC_SERVER_REC *server, const char *nick,
 	g_return_val_if_fail(nick != NULL, NULL);
 	g_return_val_if_fail(address != NULL, NULL);
 
+	g_return_val_if_fail(g_hash_table_lookup(server->splits, nick) == NULL);
+
 	/* get splitted servers */
 	dupservers = g_strdup(servers);
 	p = strchr(dupservers, ' ');