diff --git a/usb_driver.c b/usb_driver.c
index 772536d..ff3f808 100644
--- a/usb_driver.c
+++ b/usb_driver.c
@@ -30,6 +30,7 @@ static uint8_t rx_buf[USB_MAX_FS_PCKT_SIZE_NON_ISOCHRONOUS] DWORD_ALIGN; // rece
 
 // static uint8_t event_queue_mem[Q_REQ_MEM_SIZE_T(USB_EVENT_QUEUE_LENGTH, USBDRV_EventCompound)] DWORD_ALIGN; // backing memory for the event queue
 
+#ifdef USBDBGMSG
 static const char *FIFO_STATUS_STR[6] = {
     "GLOBAL OUT NAK",
     "OUT DATA RECV",
@@ -37,6 +38,7 @@ static const char *FIFO_STATUS_STR[6] = {
     "OUT SETUP CPLT",
     "",
     "OUT SETUP RECV"};
+#endif
 
 // ---------------