diff --git a/src/supported.c b/src/supported.c
index e788ad5..b8cb37a 100644
--- a/src/supported.c
+++ b/src/supported.c
@@ -324,4 +324,5 @@ init_isupport(void)
 	add_isupport("FNC", isupport_string, "");
 	add_isupport("TARGMAX", isupport_targmax, NULL);
 	add_isupport("EXTBAN", isupport_extban, NULL);
+	add_isupport("WHOX", isupport_string, "");
 }