diff --git a/board/spi_flasher.h b/board/spi_flasher.h
index ab6960c86ce98e..b1bba71d4623c4 100644
--- a/board/spi_flasher.h
+++ b/board/spi_flasher.h
@@ -183,7 +183,7 @@ void CAN1_RX0_IRQHandler(void) {
     if ((CAN->sFIFOMailBox[0].RIR>>21) == CAN_BL_INPUT) {
       uint8_t dat[8];
       for (int i = 0; i < 8; i++) {
-        dat[0] = GET_BYTE(&CAN->sFIFOMailBox[0], i);
+        dat[i] = GET_BYTE(&CAN->sFIFOMailBox[0], i);
       }
       uint8_t odat[8];
       uint8_t type = dat[0] & 0xF0;