diff --git a/degesch.c b/degesch.c
index 76721e5..10f96af 100644
--- a/degesch.c
+++ b/degesch.c
@@ -3022,7 +3022,7 @@ irc_skip_statusmsg (struct server *s, const char *target)
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 
-// As of 2015, everything should be in UTF-8.  And if it's not, we'll decode it
+// As of 2020, everything should be in UTF-8.  And if it's not, we'll decode it
 // as ISO Latin 1.  This function should not be called on the whole message.
 static char *
 irc_to_utf8 (const char *text)
@@ -7811,9 +7811,30 @@ irc_process_numeric (struct server *s,
 	strv_free (&copy);
 }
 
+static void
+irc_fix_cut_off_utf8 (char **line)
+{
+	// A variation on utf8_validate(), we need to detect the -2 return
+	const char *p = *line, *end = strchr (p, 0);
+	int32_t codepoint;
+	while ((codepoint = utf8_decode (&p, end - p)) >= 0
+		&& codepoint <= 0x10FFFF /* TODO: move this check into a function */)
+		;
+	if (codepoint != -2)
+		return;
+
+	struct str fixed_up = str_make ();
+	str_append_data (&fixed_up, *line, p - *line);
+	str_append (&fixed_up, "\xEF\xBF\xBD" /* U+FFFD */);
+	cstr_set (line, str_steal (&fixed_up));
+}
+
 static void
 irc_process_message (const struct irc_message *msg, struct server *s)
 {
+	if (msg->params.len)
+		irc_fix_cut_off_utf8 (&msg->params.vector[msg->params.len - 1]);
+
 	// TODO: make use of IRCv3.2 server-time (with fallback to unixtime_msec())
 	//   -> change all calls to log_{server,nick,outcoming,ctcp}*() to take
 	//   an extra argument specifying time