diff --git a/arch/arm64/boot/dts/amlogic/meson-a1.dtsi b/arch/arm64/boot/dts/amlogic/meson-a1.dtsi
index 1eba0afb3fd9..f7f25a10f409 100644
--- a/arch/arm64/boot/dts/amlogic/meson-a1.dtsi
+++ b/arch/arm64/boot/dts/amlogic/meson-a1.dtsi
@@ -233,6 +233,7 @@ mux {
 						groups = "uart_a_tx",
 							 "uart_a_rx";
 						function = "uart_a";
+						bias-pull-up;
 					};
 				};