diff --git a/degesch.c b/degesch.c
index 1d5e3ee..4e7b3d6 100644
--- a/degesch.c
+++ b/degesch.c
@@ -2640,8 +2640,11 @@ irc_handle_nick (struct app_context *ctx, const struct irc_message *msg)
 		str_map_set (&ctx->irc_buffer_map, new_nickname, pm_buffer);
 		str_map_set (&ctx->irc_buffer_map, user->nickname, NULL);
 
+		char *who = irc_is_this_us (ctx, msg->prefix)
+			? irc_to_utf8 (ctx, msg->prefix)
+			: NULL;
 		buffer_send (ctx, pm_buffer, BUFFER_LINE_NICK, 0,
-			.who    = irc_to_utf8 (ctx, msg->prefix),
+			.who    = who,
 			.object = irc_to_utf8 (ctx, new_nickname));
 		// TODO: use a full weechat-style buffer name here
 		buffer_rename (ctx, pm_buffer, new_nickname);