diff --git a/arch/arm/boot/dts/r8a7791-koelsch.dts b/arch/arm/boot/dts/r8a7791-koelsch.dts
index 2a0569d93b6ee..22edf3efe4c86 100644
--- a/arch/arm/boot/dts/r8a7791-koelsch.dts
+++ b/arch/arm/boot/dts/r8a7791-koelsch.dts
@@ -354,6 +354,8 @@
 		compatible = "spansion,s25fl512s";
 		reg = <0>;
 		spi-max-frequency = <30000000>;
+		spi-tx-bus-width = <4>;
+		spi-rx-bus-width = <4>;
 		m25p,fast-read;
 
 		partition@0 {