diff --git a/arch/arm64/boot/dts/renesas/r8a7796-m3ulcb.dts b/arch/arm64/boot/dts/renesas/r8a7796-m3ulcb.dts
index 2f8f183ea0cd..5567c46f3753 100644
--- a/arch/arm64/boot/dts/renesas/r8a7796-m3ulcb.dts
+++ b/arch/arm64/boot/dts/renesas/r8a7796-m3ulcb.dts
@@ -60,6 +60,10 @@ &extal_clk {
 	clock-frequency = <16666666>;
 };
 
+&extalr_clk {
+	clock-frequency = <32768>;
+};
+
 &pfc {
 	pinctrl-0 = <&scif_clk_pins>;
 	pinctrl-names = "default";