diff --git a/drivers/st/usb/stm32mp1_usb.c b/drivers/st/usb/stm32mp1_usb.c
index 9a49690..78890f5 100644
--- a/drivers/st/usb/stm32mp1_usb.c
+++ b/drivers/st/usb/stm32mp1_usb.c
@@ -4,6 +4,7 @@
  * SPDX-License-Identifier: BSD-3-Clause
  */
 
+#include <assert.h>
 #include <stdint.h>
 
 #include <arch_helpers.h>
@@ -794,7 +795,7 @@
 	uint32_t epint;
 	uint32_t epnum;
 	uint32_t temp;
-	enum usb_status ret;
+	enum usb_status __unused ret;
 
 	if (usb_dwc2_get_mode(handle) != USB_OTG_MODE_DEVICE) {
 		return USB_NOTHING;
@@ -947,9 +948,7 @@
 
 		/* Setup EP0 to receive SETUP packets */
 		ret = usb_dwc2_ep0_out_start(handle);
-		if (ret != USBD_OK) {
-			return ret;
-		}
+		assert(ret == USBD_OK);
 
 		mmio_write_32(usb_base_addr + OTG_GINTSTS, OTG_GINTSTS_USBRST);
 
@@ -959,9 +958,7 @@
 	/* Handle enumeration done interrupt */
 	if ((usb_dwc2_read_int(handle) & OTG_GINTSTS_ENUMDNE) != 0U) {
 		ret = usb_dwc2_activate_setup(handle);
-		if (ret != USBD_OK) {
-			return ret;
-		}
+		assert(ret == USBD_OK);
 
 		mmio_clrbits_32(usb_base_addr + OTG_GUSBCFG, OTG_GUSBCFG_TRDT);