diff --git a/mesonbuild/coredata.py b/mesonbuild/coredata.py
index b8702d5e9e93..356e655b3cb8 100644
--- a/mesonbuild/coredata.py
+++ b/mesonbuild/coredata.py
@@ -857,10 +857,10 @@ def save(obj: CoreData, build_dir: str) -> str:
 
 def register_builtin_arguments(parser: argparse.ArgumentParser) -> None:
     for n, b in options.BUILTIN_OPTIONS.items():
-        b.add_to_argparse(str(n), parser, '')
+        b.add_to_argparse(n, parser, '')
     for n, b in options.BUILTIN_OPTIONS_PER_MACHINE.items():
-        b.add_to_argparse(str(n), parser, ' (just for host machine)')
-        b.add_to_argparse(str(n.as_build()), parser, ' (just for build machine)')
+        b.add_to_argparse(n, parser, ' (just for host machine)')
+        b.add_to_argparse(n.as_build(), parser, ' (just for build machine)')
     parser.add_argument('-D', action='append', dest='projectoptions', default=[], metavar="option",
                         help='Set the value of an option, can be used several times to set multiple options.')
 
diff --git a/mesonbuild/options.py b/mesonbuild/options.py
index 047480297443..ae923fec2f63 100644
--- a/mesonbuild/options.py
+++ b/mesonbuild/options.py
@@ -588,7 +588,7 @@ def prefixed_default(self, name: 'OptionKey', prefix: str = '') -> T.Any:
             pass
         return self.default
 
-    def add_to_argparse(self, name: str, parser: argparse.ArgumentParser, help_suffix: str) -> None:
+    def add_to_argparse(self, name: OptionKey, parser: argparse.ArgumentParser, help_suffix: str) -> None:
         kwargs: ArgparseKWs = {}
 
         c = self._argparse_choices()
@@ -601,9 +601,9 @@ def add_to_argparse(self, name: str, parser: argparse.ArgumentParser, help_suffi
         if c and not b:
             kwargs['choices'] = c
         kwargs['default'] = argparse.SUPPRESS
-        kwargs['dest'] = name
+        kwargs['dest'] = str(name)
 
-        cmdline_name = self.argparse_name_to_arg(name)
+        cmdline_name = self.argparse_name_to_arg(str(name))
         parser.add_argument(cmdline_name, help=h + help_suffix, **kwargs)