diff --git a/arch/arm/boot/dts/rk3188-tb.dts b/arch/arm/boot/dts/rk3188-tb.dts
index 73642d2edc1c..409052084503 100644
--- a/arch/arm/boot/dts/rk3188-tb.dts
+++ b/arch/arm/boot/dts/rk3188-tb.dts
@@ -7,7 +7,7 @@
 / {
 	memory {
 		device_type = "memory";
-		reg = <0x60000000 0x80000000>;
+		reg = <0x60000000 0x40000000>;
 	};
 
 	chosen {