diff --git a/ports/raspberrypi/boards/raspberry_pi_pico/mpconfigboard.mk b/ports/raspberrypi/boards/raspberry_pi_pico/mpconfigboard.mk
index 69ff56fef8..2c9f9e2339 100644
--- a/ports/raspberrypi/boards/raspberry_pi_pico/mpconfigboard.mk
+++ b/ports/raspberrypi/boards/raspberry_pi_pico/mpconfigboard.mk
@@ -7,3 +7,4 @@ CHIP_VARIANT = RP2040
 CHIP_FAMILY = rp2
 
 INTERNAL_FLASH_FILESYSTEM = 1
+LONGINT_IMPL = MPZ