diff --git a/picard/config_upgrade.py b/picard/config_upgrade.py
index 3aff6a9c6..702936e16 100644
--- a/picard/config_upgrade.py
+++ b/picard/config_upgrade.py
@@ -28,6 +28,7 @@ from picard import (log, config)
 # ----------------------
 # add a function here, named after the version you want upgrade to
 # ie. upgrade_to_v1_0_0_dev_1() for 1.0.0dev1
+# register it in upgrade_config()
 # and modify PICARD_VERSION to match it
 #