--- zzzz-none-000/linux-4.9.276/drivers/isdn/Kconfig	2021-07-20 14:21:16.000000000 +0000
+++ falcon-5530-750/linux-4.9.276/drivers/isdn/Kconfig	2023-04-05 08:19:01.000000000 +0000
@@ -58,6 +58,8 @@
 
 if ISDN_CAPI
 
+source "drivers/isdn/capi_oslib/Kconfig"
+
 source "drivers/isdn/capi/Kconfig"
 
 source "drivers/isdn/hardware/Kconfig"