diff --git a/arch/sandbox/dts/test.dts b/arch/sandbox/dts/test.dts
index e91387a..1399a14 100644
--- a/arch/sandbox/dts/test.dts
+++ b/arch/sandbox/dts/test.dts
@@ -796,6 +796,7 @@
 	gpio-wdt {
 		gpios = <&gpio_a 7 0>;
 		compatible = "linux,wdt-gpio";
+		hw_margin_ms = <100>;
 		always-running;
 	};
 
@@ -1278,6 +1279,7 @@
 
 	wdt0: wdt@0 {
 		compatible = "sandbox,wdt";
+		hw_margin_ms = <200>;
 	};
 
 	axi: axi@0 {