diff --git a/Mac/scripts/EditPythonPrefs.py b/Mac/scripts/EditPythonPrefs.py
index 5ceb1812365..78da11bf596 100644
--- a/Mac/scripts/EditPythonPrefs.py
+++ b/Mac/scripts/EditPythonPrefs.py
@@ -36,6 +36,7 @@ OPT_DIALOG_ID = 510
 
 # Map dialog item numbers to option names (and the reverse)
 opt_dialog_map = [
+	None,
 	None,
 	None,
 	"inspect",