diff --git a/arch/arm/boot/dts/r8a7778-bockw.dts b/arch/arm/boot/dts/r8a7778-bockw.dts
index 274a1b6fe32998b8fa3e64265f82be54c7c6391c..00119754f7f08541c53076596c7d3fe2c7fa6e7c 100644
--- a/arch/arm/boot/dts/r8a7778-bockw.dts
+++ b/arch/arm/boot/dts/r8a7778-bockw.dts
@@ -61,6 +61,10 @@
 	};
 };
 
+&extal_clk {
+	clock-frequency = <33333333>;
+};
+
 &mmcif {
 	pinctrl-0 = <&mmc_pins>;
 	pinctrl-names = "default";