diff --git a/degesch.c b/degesch.c
index 329ab5d..b65e213 100644
--- a/degesch.c
+++ b/degesch.c
@@ -1961,6 +1961,28 @@ irc_handle_notice (struct app_context *ctx, const struct irc_message *msg)
 static void
 irc_handle_part (struct app_context *ctx, const struct irc_message *msg)
 {
+	if (!msg->prefix || msg->params.len < 1)
+		return;
+
+	char *nickname = irc_cut_nickname (msg->prefix);
+	struct user *user = str_map_find (&ctx->irc_users, nickname);
+	free (nickname);
+	if (!user)
+		return;
+
+	const char *target = msg->params.vector[0];
+	if (!irc_is_channel (ctx, target))
+		return;
+
+	const char *message = NULL;
+	if (msg->params.len > 1)
+		message = msg->params.vector[1];
+
+	struct channel *channel = str_map_find (&ctx->irc_channels, target);
+	struct buffer *buffer = str_map_find (&ctx->irc_buffer_map, target);
+	hard_assert ((channel && buffer) ||
+		(channel && !buffer) || (!channel && !buffer));
+
 	// TODO: remove user from the channel
 	// TODO: log a message
 }