diff --git a/arch/arm/boot/dts/r8a7793.dtsi b/arch/arm/boot/dts/r8a7793.dtsi
index 8d02aacf2892..a7d11b9f3555 100644
--- a/arch/arm/boot/dts/r8a7793.dtsi
+++ b/arch/arm/boot/dts/r8a7793.dtsi
@@ -666,7 +666,7 @@
 	scifb0: serial@e6c20000 {
 		compatible = "renesas,scifb-r8a7793",
 			     "renesas,rcar-gen2-scifb", "renesas,scifb";
-		reg = <0 0xe6c20000 0 64>;
+		reg = <0 0xe6c20000 0 0x100>;
 		interrupts = <GIC_SPI 148 IRQ_TYPE_LEVEL_HIGH>;
 		clocks = <&mstp2_clks R8A7793_CLK_SCIFB0>;
 		clock-names = "fck";
@@ -680,7 +680,7 @@
 	scifb1: serial@e6c30000 {
 		compatible = "renesas,scifb-r8a7793",
 			     "renesas,rcar-gen2-scifb", "renesas,scifb";
-		reg = <0 0xe6c30000 0 64>;
+		reg = <0 0xe6c30000 0 0x100>;
 		interrupts = <GIC_SPI 149 IRQ_TYPE_LEVEL_HIGH>;
 		clocks = <&mstp2_clks R8A7793_CLK_SCIFB1>;
 		clock-names = "fck";
@@ -694,7 +694,7 @@
 	scifb2: serial@e6ce0000 {
 		compatible = "renesas,scifb-r8a7793",
 			     "renesas,rcar-gen2-scifb", "renesas,scifb";
-		reg = <0 0xe6ce0000 0 64>;
+		reg = <0 0xe6ce0000 0 0x100>;
 		interrupts = <GIC_SPI 150 IRQ_TYPE_LEVEL_HIGH>;
 		clocks = <&mstp2_clks R8A7793_CLK_SCIFB2>;
 		clock-names = "fck";