diff --git a/arch/arm/dts/stm32mp157a-dk1-u-boot.dtsi b/arch/arm/dts/stm32mp157a-dk1-u-boot.dtsi
index c52abeb..3fedb6f 100644
--- a/arch/arm/dts/stm32mp157a-dk1-u-boot.dtsi
+++ b/arch/arm/dts/stm32mp157a-dk1-u-boot.dtsi
@@ -20,6 +20,21 @@
 		st,fastboot-gpios = <&gpioa 13 GPIO_ACTIVE_LOW>;
 		st,stm32prog-gpios = <&gpioa 14 GPIO_ACTIVE_LOW>;
 	};
+
+	firmware {
+		optee {
+			compatible = "linaro,optee-tz";
+			method = "smc";
+		};
+	};
+
+	reserved-memory {
+		optee@de000000 {
+			reg = <0xde000000 0x02000000>;
+			no-map;
+		};
+	};
+
 	led {
 		red {
 			label = "error";