diff --git a/degesch.c b/degesch.c
index 2388080..85e43c6 100644
--- a/degesch.c
+++ b/degesch.c
@@ -863,6 +863,8 @@ struct channel
 
 	struct channel_user *users;         ///< Channel users
 	struct str_vector names_buf;        ///< Buffer for RPL_NAMREPLY
+
+	bool left_manually;                 ///< Don't rejoin on reconnect
 };
 
 static struct channel *
@@ -4851,6 +4853,9 @@ irc_handle_join (struct server *s, const struct irc_message *msg)
 	if (!channel)
 		return;
 
+	// Reset the field so that we rejoin the channel after reconnecting
+	channel->left_manually = false;
+
 	// Add the user to the channel
 	char *nickname = irc_cut_nickname (msg->prefix);
 	irc_channel_link_user (channel, irc_get_or_make_user (s, nickname), "");
@@ -5468,11 +5473,18 @@ irc_on_registered (struct server *s, const char *nickname)
 	// XXX: we can also use WHOIS if it's not supported (optional by RFC 2812)
 	irc_send (s, "USERHOST %s", s->irc_user->nickname);
 
+	// TODO: split autojoin at commas and make a joined set with regular rejoins
 	const char *autojoin = get_config_string (s->config, "autojoin");
 	if (autojoin)
 		irc_send (s, "JOIN :%s", autojoin);
 
-	// TODO: rejoin all current channels (mark those we've left manually?)
+	struct str_map_iter iter;
+	str_map_iter_init (&iter, &s->irc_channels);
+
+	struct channel *channel;
+	while ((channel = str_map_iter_next (&iter)))
+		if (!channel->left_manually)
+			irc_send (s, "JOIN :%s", channel->name);
 }
 
 static void
@@ -6623,6 +6635,19 @@ show_buffers_list (struct app_context *ctx)
 		log_global_indent (ctx, "  [#d] #s", i++, iter->name);
 }
 
+static void
+part_channel (struct server *s, const char *channel_name, const char *reason)
+{
+	if (*reason)
+		irc_send (s, "PART %s :%s", channel_name, reason);
+	else
+		irc_send (s, "PART %s", channel_name);
+
+	struct channel *channel;
+	if ((channel = str_map_find (&s->irc_channels, channel_name)))
+		channel->left_manually = true;
+}
+
 static void
 handle_buffer_close (struct app_context *ctx, struct handler_args *a)
 {
@@ -6643,7 +6668,7 @@ handle_buffer_close (struct app_context *ctx, struct handler_args *a)
 	{
 		// The user would be unable to recreate the buffer otherwise
 		if (buffer->type == BUFFER_CHANNEL)
-			irc_send (buffer->server, "PART %s", buffer->channel->name);
+			part_channel (buffer->server, buffer->channel->name, "");
 
 		if (buffer == ctx->current_buffer)
 			buffer_activate (ctx, ctx->last_buffer
@@ -7084,15 +7109,6 @@ handle_command_join (struct handler_args *a)
 	return true;
 }
 
-static void
-part_channel (struct server *s, const char *channel_name, const char *reason)
-{
-	if (*reason)
-		irc_send (s, "PART %s :%s", channel_name, reason);
-	else
-		irc_send (s, "PART %s", channel_name);
-}
-
 static bool
 handle_command_part (struct handler_args *a)
 {