diff --git a/ports/cc3200/boards/make-pins.py b/ports/cc3200/boards/make-pins.py
index da04d8e36..f1bdf15a3 100644
--- a/ports/cc3200/boards/make-pins.py
+++ b/ports/cc3200/boards/make-pins.py
@@ -1,6 +1,9 @@
 #!/usr/bin/env python
 """Generates the pins file for the CC3200."""
 
+# Do not use this as a reference for new ports. See tools/boardgen.py and e.g.
+# ports/stm32/boards/make-pins.py.
+
 from __future__ import print_function
 
 import argparse
diff --git a/ports/nrf/boards/make-pins.py b/ports/nrf/boards/make-pins.py
index 6932a18d6..57e815a43 100644
--- a/ports/nrf/boards/make-pins.py
+++ b/ports/nrf/boards/make-pins.py
@@ -1,6 +1,9 @@
 #!/usr/bin/env python
 """Creates the pin file for the nRF5."""
 
+# Do not use this as a reference for new ports. See tools/boardgen.py and e.g.
+# ports/stm32/boards/make-pins.py.
+
 from __future__ import print_function
 
 import argparse