diff --git a/src/portable/st/synopsys/dcd_synopsys.c b/src/portable/st/synopsys/dcd_synopsys.c
index 4e385f69..548438b6 100644
--- a/src/portable/st/synopsys/dcd_synopsys.c
+++ b/src/portable/st/synopsys/dcd_synopsys.c
@@ -555,6 +555,8 @@ void dcd_disconnect(uint8_t rhport)
 
 bool dcd_edpt_open (uint8_t rhport, tusb_desc_endpoint_t const * desc_edpt)
 {
+  (void) rhport;
+
   USB_OTG_GlobalTypeDef * usb_otg = GLOBAL_BASE(rhport);
   USB_OTG_DeviceTypeDef * dev = DEVICE_BASE(rhport);
   USB_OTG_OUTEndpointTypeDef * out_ep = OUT_EP_BASE(rhport);