diff --git a/dts/arm/renesas/ra/ra8/ra8x1.dtsi b/dts/arm/renesas/ra/ra8/ra8x1.dtsi
index 944ba690a9e..95920b98671 100644
--- a/dts/arm/renesas/ra/ra8/ra8x1.dtsi
+++ b/dts/arm/renesas/ra/ra8/ra8x1.dtsi
@@ -582,6 +582,15 @@
 			};
 		};
 
+		ospi0: ospi@40268000 {
+			compatible = "renesas,ra-ospi-b";
+			reg = <0x40268000 0x19c>;
+			#address-cells = <1>;
+			#size-cells = <1>;
+			clocks = <&octaspiclk MSTPB 16>;
+			status = "disabled";
+		};
+
 		option_setting_ofs: option_setting_ofs@300a100 {
 			compatible = "zephyr,memory-region";
 			reg = <0x0300a100 0x18>;
diff --git a/dts/bindings/flash_controller/renesas,ra-ospi-b-nor.yaml b/dts/bindings/flash_controller/renesas,ra-ospi-b-nor.yaml
index 0a4c53b02cc..07c83927259 100644
--- a/dts/bindings/flash_controller/renesas,ra-ospi-b-nor.yaml
+++ b/dts/bindings/flash_controller/renesas,ra-ospi-b-nor.yaml
@@ -5,7 +5,7 @@ description: Renesas RA OSPI FLASH
 
 compatible: "renesas,ra-ospi-b-nor"
 
-include: [base.yaml]
+include: [flash-controller.yaml]
 
 on-bus: ospi
 
@@ -14,11 +14,6 @@ properties:
     required: true
     description: Flash Memory base address and size in bytes
 
-  size:
-    type: int
-    required: true
-    description: Flash Memory size
-
   protocol-mode:
     type: int
     required: true