diff --git a/mesonbuild/options.py b/mesonbuild/options.py
index 1cee977cbc4f..75c4205e9897 100644
--- a/mesonbuild/options.py
+++ b/mesonbuild/options.py
@@ -941,13 +941,6 @@ def sanitize_dir_option_value(self, prefix: str, option: OptionKey, value: T.Any
         # .as_posix() keeps the posix-like file separators Meson uses.
         return value.as_posix()
 
-    def _set_dependents(self, key: OptionKey, value: str) -> None:
-        opt, debug = self.DEFAULT_DEPENDENTS[value]
-        dkey = key.evolve(name='debug')
-        optkey = key.evolve(name='optimization')
-        self.options[dkey].set_value(debug)
-        self.options[optkey].set_value(opt)
-
     def set_option(self, key: OptionKey, new_value: ElementaryOptionValues, first_invocation: bool = False) -> bool:
         if key.name == 'prefix':
             assert isinstance(new_value, str), 'for mypy'
@@ -997,7 +990,11 @@ def replace(v: T.Any) -> T.Any:
 
         if changed and key.name == 'buildtype':
             assert isinstance(new_value, str), 'for mypy'
-            self._set_dependents(key, new_value)
+            opt, debug = self.DEFAULT_DEPENDENTS[value]
+            dkey = key.evolve(name='debug')
+            optkey = key.evolve(name='optimization')
+            self.options[dkey].set_value(debug)
+            self.options[optkey].set_value(opt)
 
         return changed