diff --git a/lib/README b/lib/README
index bf80a105..a827dc22 100644
--- a/lib/README
+++ b/lib/README
@@ -146,4 +146,4 @@ used to upload firmware to devices flashed with the CanBoot bootloader.
 
 The can2040 directory contains code from:
   https://github.com/KevinOConnor/can2040
-revision 53c09fb06a8eac90a6941e988d09d08b8e16ba78.
+revision 177b0073fe6f19281ee7f7fdbe9599e32d1b4b8b.
diff --git a/lib/can2040/can2040.c b/lib/can2040/can2040.c
index f39636ae..fb9e3fb6 100644
--- a/lib/can2040/can2040.c
+++ b/lib/can2040/can2040.c
@@ -347,6 +347,8 @@ pio_sm_setup(struct can2040 *cd)
     pio_hw_t *pio_hw = cd->pio_hw;
     pio_hw->ctrl = PIO_CTRL_SM_RESTART_BITS | PIO_CTRL_CLKDIV_RESTART_BITS;
     pio_hw->fdebug = 0xffffffff;
+    pio_hw->irq = 0xff;
+    pio_signal_set_txpending(cd);
 
     // Load pio program
     int i;