diff --git a/sound/soc/rockchip/Kconfig b/sound/soc/rockchip/Kconfig
index 957046ac6c8c..d88555e0c389 100644
--- a/sound/soc/rockchip/Kconfig
+++ b/sound/soc/rockchip/Kconfig
@@ -19,6 +19,7 @@ config SND_SOC_ROCKCHIP_PDM
 	tristate "Rockchip PDM Controller Driver"
 	depends on CLKDEV_LOOKUP && SND_SOC_ROCKCHIP
 	select SND_SOC_GENERIC_DMAENGINE_PCM
+	select RATIONAL
 	help
 	  Say Y or M if you want to add support for PDM driver for
 	  Rockchip PDM Controller. The Controller supports up to maximum of