diff --git a/drivers/usb/mtu3/mtu3_gadget.c b/drivers/usb/mtu3/mtu3_gadget.c
index a3e1105c5c66..b7a6363f387a 100644
--- a/drivers/usb/mtu3/mtu3_gadget.c
+++ b/drivers/usb/mtu3/mtu3_gadget.c
@@ -77,7 +77,7 @@ static int mtu3_ep_enable(struct mtu3_ep *mep)
 		if (usb_endpoint_xfer_int(desc) ||
 				usb_endpoint_xfer_isoc(desc)) {
 			interval = desc->bInterval;
-			interval = clamp_val(interval, 1, 16) - 1;
+			interval = clamp_val(interval, 1, 16);
 			if (usb_endpoint_xfer_isoc(desc) && comp_desc)
 				mult = comp_desc->bmAttributes;
 		}
@@ -89,7 +89,7 @@ static int mtu3_ep_enable(struct mtu3_ep *mep)
 		if (usb_endpoint_xfer_isoc(desc) ||
 				usb_endpoint_xfer_int(desc)) {
 			interval = desc->bInterval;
-			interval = clamp_val(interval, 1, 16) - 1;
+			interval = clamp_val(interval, 1, 16);
 			mult = usb_endpoint_maxp_mult(desc) - 1;
 		}
 		break;