diff --git a/degesch.c b/degesch.c
index acd4856..f997471 100644
--- a/degesch.c
+++ b/degesch.c
@@ -2919,6 +2919,29 @@ irc_left_channel (struct channel *channel)
 		irc_channel_unlink_user (channel, iter);
 }
 
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+
+static void
+irc_rehash_and_fix_conflicts (struct server *s)
+{
+	// TODO
+}
+
+static void
+irc_set_casemapping (struct server *s,
+	irc_tolower_fn tolower, irc_strxfrm_fn strxfrm)
+{
+	if (tolower == s->irc_tolower
+	 && strxfrm == s->irc_strxfrm)
+		return;
+
+	s->irc_tolower = tolower;
+	s->irc_strxfrm = strxfrm;
+
+	// Ideally we would never have to do this but I can't think of a workaround
+	irc_rehash_and_fix_conflicts (s);
+}
+
 // --- Core functionality ------------------------------------------------------
 
 // Most of the core IRC code comes from ZyklonB which is mostly blocking.
@@ -3267,15 +3290,11 @@ on_irc_disconnected (struct server *s)
 
 	s->cap_echo_message = false;
 
-	irc_tolower_fn old_tolower = s->irc_tolower;
-	irc_strxfrm_fn old_strxfrm = s->irc_strxfrm;
+	// Need to call this before server_init_specifics()
+	irc_set_casemapping (s, irc_tolower, irc_strxfrm);
+
 	server_free_specifics (s);
 	server_init_specifics (s);
-	// TODO: compare with the original functions and merge users and their
-	//   buffers as necessary; ideally we would never have to do this but
-	//   I can't think of any good workaround
-	s->irc_tolower = old_tolower;
-	s->irc_strxfrm = old_strxfrm;
 
 	// Take any relevant actions
 	if (s->ctx->quitting)
@@ -5203,25 +5222,13 @@ irc_handle_isupport_prefix (struct server *s, char *value)
 static void
 irc_handle_isupport_casemapping (struct server *s, char *value)
 {
-	// TODO: reinitialize hashtables with the new tolower() and strxfrm(),
-	//   note that collisions may arise on reconnecting
-
 	if      (!strcmp (value, "ascii"))
-	{
-		s->irc_tolower = tolower_ascii;
-		s->irc_strxfrm = tolower_ascii_strxfrm;
-	}
+		irc_set_casemapping (s, tolower_ascii, tolower_ascii_strxfrm);
 	else if (!strcmp (value, "rfc1459"))
-	{
-		s->irc_tolower = irc_tolower;
-		s->irc_strxfrm = irc_strxfrm;
-	}
+		irc_set_casemapping (s, irc_tolower,   irc_strxfrm);
 	else if (!strcmp (value, "rfc1459-strict"))
-	{
 		// TODO: implement
-		s->irc_tolower = irc_tolower;
-		s->irc_strxfrm = irc_strxfrm;
-	}
+		irc_set_casemapping (s, irc_tolower,   irc_strxfrm);
 }
 
 static void