diff --git a/boards/arm/arduino_portenta_h7/arduino_portenta_h7-common.dtsi b/boards/arm/arduino_portenta_h7/arduino_portenta_h7-common.dtsi
index e8630e6bc05..094fc29ed13 100644
--- a/boards/arm/arduino_portenta_h7/arduino_portenta_h7-common.dtsi
+++ b/boards/arm/arduino_portenta_h7/arduino_portenta_h7-common.dtsi
@@ -25,6 +25,11 @@
 	};
 };
 
+&clk_hsi48 {
+	/* HSI48 required for USB */
+	status = "okay";
+};
+
 &rcc {
 	d1cpre = <1>;
 	hpre = <1>;
diff --git a/boards/arm/disco_l475_iot1/disco_l475_iot1.dts b/boards/arm/disco_l475_iot1/disco_l475_iot1.dts
index 8a25b416a9e..4c09887437b 100644
--- a/boards/arm/disco_l475_iot1/disco_l475_iot1.dts
+++ b/boards/arm/disco_l475_iot1/disco_l475_iot1.dts
@@ -90,6 +90,12 @@
 	status = "okay";
 };
 
+&clk_msi {
+	status = "okay";
+	msi-pll-mode;
+	msi-range = <11>; /* 48MHz USB bus clk */
+};
+
 &pll {
 	div-m = <1>;
 	mul-n = <20>;