diff --git a/arch/arm64/boot/dts/renesas/r9a09g056.dtsi b/arch/arm64/boot/dts/renesas/r9a09g056.dtsi
index 40525470194e..7ccddd6a4a9a 100644
--- a/arch/arm64/boot/dts/renesas/r9a09g056.dtsi
+++ b/arch/arm64/boot/dts/renesas/r9a09g056.dtsi
@@ -1327,6 +1327,7 @@ usb20phyrst: usb20phy-reset@15830000 {
 			resets = <&cpg 0xaf>;
 			power-domains = <&cpg>;
 			#reset-cells = <0>;
+			#mux-state-cells = <1>;
 			status = "disabled";
 		};