diff --git a/src/irc.c b/src/irc.c
index 63a602d..88f9b4e 100644
--- a/src/irc.c
+++ b/src/irc.c
@@ -1030,6 +1030,31 @@ static int irc_cli_pass(bip_t *bip, struct link_client *ic, struct line *line)
 	return OK_FORGET;
 }
 
+static int irc_cli_cap(bip_t *bip, struct link_client *ic, struct line *line)
+{
+	if (irc_line_count(line) < 2)
+		return ERR_PROTOCOL;
+
+	/* When we decide to enable actual capabilities, we'll have to handle CAP
+	 * version, add a flag cap_started or similar, and handle CAP END.
+	 */
+	if (irc_line_elem_equals(line, 1, "LS")) {
+		WRITE_LINE2(CONN(ic), NULL, "CAP", "*", "LS");
+	} else if (irc_line_elem_equals(line, 1, "LIST")) {
+		WRITE_LINE3(CONN(ic), NULL, "CAP", "*", "LIST", "");
+	} else if (irc_line_elem_equals(line, 1, "REQ")) {
+		char *caps = irc_line_to_string_skip(line, 2);
+		if (caps) {
+			caps++;
+			WRITE_LINE3(CONN(ic), NULL, "CAP", "*", "NAK", caps);
+		}
+	}
+
+	if ((ic->state & IRCC_READY) == IRCC_READY)
+		return irc_cli_startup(bip, ic, line);
+	return OK_FORGET;
+}
+
 static int irc_cli_quit(struct link_client *ic, struct line *line)
 {
 	(void)ic;
@@ -1408,6 +1433,8 @@ static int irc_dispatch_logging_client(bip_t *bip, struct link_client *ic,
 		return irc_cli_user(bip, ic, line);
 	} else if (irc_line_elem_equals(line, 0, "PASS")) {
 		return irc_cli_pass(bip, ic, line);
+	} else if (irc_line_elem_equals(line, 0, "CAP")) {
+		return irc_cli_cap(bip, ic, line);
 	}
 	return OK_FORGET;
 }