diff --git a/boards/manifest_pico2.py b/boards/manifest_pico2.py
index ca9171f..f266753 100644
--- a/boards/manifest_pico2.py
+++ b/boards/manifest_pico2.py
@@ -1,5 +1,5 @@
 # micropython/ports/rp2/../../../
-MODULES_PY = "{PORT_DIR}/../../../pimoroni-pico/micropython/modules_py"
+MODULES_PY = "$(PORT_DIR)/../../../pimoroni-pico/micropython/modules_py"
 
 # SD Card
 require("sdcard")