diff --git a/arch/sandbox/dts/sandbox.dts b/arch/sandbox/dts/sandbox.dts
index 0aba6c9..1fb8225 100644
--- a/arch/sandbox/dts/sandbox.dts
+++ b/arch/sandbox/dts/sandbox.dts
@@ -70,7 +70,7 @@
 		compatible = "sandbox,gpio";
 		#gpio-cells = <1>;
 		gpio-bank-name = "a";
-		num-gpios = <20>;
+		sandbox,gpio-count = <20>;
 	};
 
 	gpio_b: gpios@1 {
@@ -78,7 +78,7 @@
 		compatible = "sandbox,gpio";
 		#gpio-cells = <2>;
 		gpio-bank-name = "b";
-		num-gpios = <10>;
+		sandbox,gpio-count = <10>;
 	};
 
 	hexagon {
diff --git a/arch/sandbox/dts/test.dts b/arch/sandbox/dts/test.dts
index c38e369..b0f0ca8 100644
--- a/arch/sandbox/dts/test.dts
+++ b/arch/sandbox/dts/test.dts
@@ -177,7 +177,7 @@
 		gpio-controller;
 		#gpio-cells = <1>;
 		gpio-bank-name = "a";
-		num-gpios = <20>;
+		sandbox,gpio-count = <20>;
 	};
 
 	gpio_b: extra-gpios {
@@ -185,7 +185,7 @@
 		gpio-controller;
 		#gpio-cells = <5>;
 		gpio-bank-name = "b";
-		num-gpios = <10>;
+		sandbox,gpio-count = <10>;
 	};
 
 	i2c@0 {