diff --git a/arch/arm/boot/dts/stm32f429.dtsi b/arch/arm/boot/dts/stm32f429.dtsi
index e9324a390ac7..557c1f482937 100644
--- a/arch/arm/boot/dts/stm32f429.dtsi
+++ b/arch/arm/boot/dts/stm32f429.dtsi
@@ -433,6 +433,8 @@
 			reg = <0x40023800 0x400>;
 			clocks = <&clk_hse>, <&clk_i2s_ckin>;
 			st,syscfg = <&pwrcfg>;
+			assigned-clocks = <&rcc 1 CLK_HSE_RTC>;
+			assigned-clock-rates = <1000000>;
 		};
 
 		dma1: dma-controller@40026000 {