diff --git a/common/usb_hc.h b/common/usb_hc.h
index dfe20703..95215841 100644
--- a/common/usb_hc.h
+++ b/common/usb_hc.h
@@ -59,7 +59,11 @@ struct usbh_urb {
     uint32_t start_frame;
     usbh_complete_callback_t complete;
     void *arg;
+#if defined(__ICCARM__) || defined(__ICCRISCV__) || defined(__ICCRX__)
+    struct usbh_iso_frame_packet *iso_packet;
+#else
     struct usbh_iso_frame_packet iso_packet[0];
+#endif
 };
 
 /**