diff --git a/tests/drivers/adc/adc_api/boards/nucleo_f746zg.overlay b/tests/drivers/adc/adc_api/boards/nucleo_f746zg.overlay
index ed807ca3ca61..35108125b690 100644
--- a/tests/drivers/adc/adc_api/boards/nucleo_f746zg.overlay
+++ b/tests/drivers/adc/adc_api/boards/nucleo_f746zg.overlay
@@ -17,6 +17,7 @@
 	dma-names = "dma";
 
 	pinctrl-0 = <&adc1_in0_pa0 &adc1_in3_pa3>;
+	st,adc-prescaler = <4>;
 	#address-cells = <1>;
 	#size-cells = <0>;