diff --git a/src/api-isupport.c b/src/api-isupport.c
index 8dcd9ff9b..10ebd43f0 100644
--- a/src/api-isupport.c
+++ b/src/api-isupport.c
@@ -141,6 +141,7 @@ void isupport_init(void)
 		IsupportSet(NULL, "UHNAMES", NULL);
 	else
 		IsupportDelByName("UHNAMES");
+	IsupportSet(NULL, "DEAF", "d");
 	set_isupport_extban(); /* EXTBAN=xyz */
 }