diff --git a/mesonbuild/mesonmain.py b/mesonbuild/mesonmain.py
index 516c41193..d7bccdb53 100644
--- a/mesonbuild/mesonmain.py
+++ b/mesonbuild/mesonmain.py
@@ -27,6 +27,8 @@ from .environment import detect_msys2_arch
 from .wrap import wraptool
 
 
+# Note: when adding arguments, please also add them to the completion
+# scripts in $MESONSRC/data/shell-completions/
 class CommandLineParser:
     def __init__(self):
         self.commands = {}