diff --git a/src/irc.c b/src/irc.c
index e4d3b79..f36c0df 100644
--- a/src/irc.c
+++ b/src/irc.c
@@ -1878,7 +1878,8 @@ void irc_server_shutdown(struct link_server *s)
 
 	if (LINK(s)->prev_ircmask)
 		free(LINK(s)->prev_ircmask);
-	LINK(s)->prev_ircmask = strdup(s->irc_mask);
+	if (s->irc_mask)
+		LINK(s)->prev_ircmask = strdup(s->irc_mask);
 }