diff --git a/tests/drivers/spi/spi_loopback/boards/nucleo_g474re.overlay b/tests/drivers/spi/spi_loopback/boards/nucleo_g474re.overlay
index b317c810ff9..d2151a4f832 100644
--- a/tests/drivers/spi/spi_loopback/boards/nucleo_g474re.overlay
+++ b/tests/drivers/spi/spi_loopback/boards/nucleo_g474re.overlay
@@ -30,3 +30,11 @@
 &dmamux1 {
 	status = "okay";
 };
+
+&rcc {
+	/*
+	 * Reduce bus clock speed to be able to reach
+	 * SPI_LOOPBACK_SLOW_FREQ = 500000 with max prescaler 256
+	 */
+	apb2-prescaler = <2>;
+};