diff --git a/drivers/isdn/mISDN/Kconfig b/drivers/isdn/mISDN/Kconfig
index 26cf0ac9c4ad..c9a53c222472 100644
--- a/drivers/isdn/mISDN/Kconfig
+++ b/drivers/isdn/mISDN/Kconfig
@@ -13,6 +13,7 @@ if MISDN != n
 config MISDN_DSP
 	tristate "Digital Audio Processing of transparent data"
 	depends on MISDN
+	select BITREVERSE
 	help
 	  Enable support for digital audio processing capability.