diff --git a/mesonbuild/interpreter/interpreter.py b/mesonbuild/interpreter/interpreter.py
index 04fa67a9536f..07e28c295351 100644
--- a/mesonbuild/interpreter/interpreter.py
+++ b/mesonbuild/interpreter/interpreter.py
@@ -269,7 +269,6 @@ def __init__(
                 subproject_dir: str = 'subprojects',
                 default_project_options: T.Optional[T.Dict[OptionKey, str]] = None,
                 ast: T.Optional[mparser.CodeBlockNode] = None,
-                is_translated: bool = False,
                 relaxations: T.Optional[T.Set[InterpreterRuleRelaxation]] = None,
                 user_defined_options: T.Optional[coredata.SharedCMDOptions] = None,
             ) -> None:
@@ -283,6 +282,7 @@ def __init__(
         self.modules: T.Dict[str, NewExtensionModule] = {}
         self.subproject_dir = subproject_dir
         self.relaxations = relaxations or set()
+        self.build_def_files: mesonlib.OrderedSet[str] = mesonlib.OrderedSet()
         if ast is None:
             self.load_root_meson_file()
         else:
@@ -305,16 +305,6 @@ def __init__(
         self.build_holder_map()
         self.user_defined_options = user_defined_options
         self.compilers: PerMachine[T.Dict[str, 'compilers.Compiler']] = PerMachine({}, {})
-
-        # build_def_files needs to be defined before parse_project is called
-        #
-        # For non-meson subprojects, we'll be using the ast. Even if it does
-        # exist we don't want to add a dependency on it, it's autogenerated
-        # from the actual build files, and is just for reference.
-        self.build_def_files: mesonlib.OrderedSet[str] = mesonlib.OrderedSet()
-        if not is_translated:
-            build_filename = os.path.join(self.subdir, environment.build_filename)
-            self.build_def_files.add(build_filename)
         self.parse_project()
         self._redetect_machines()
 
@@ -339,6 +329,11 @@ def _redetect_machines(self) -> None:
         self.builtin['target_machine'] = \
             OBJ.MachineHolder(self.build.environment.machines.target, self)
 
+    def load_root_meson_file(self) -> None:
+        build_filename = os.path.join(self.subdir, environment.build_filename)
+        self.build_def_files.add(build_filename)
+        super().load_root_meson_file()
+
     def build_func_dict(self) -> None:
         self.funcs.update({'add_global_arguments': self.func_add_global_arguments,
                            'add_global_link_arguments': self.func_add_global_link_arguments,
@@ -968,8 +963,7 @@ def _do_subproject_meson(self, subp_name: str, subdir: str,
 
             new_build = self.build.copy()
             subi = Interpreter(new_build, self.backend, subp_name, subdir, self.subproject_dir,
-                               default_options, ast=ast, is_translated=(ast is not None),
-                               relaxations=relaxations,
+                               default_options, ast=ast, relaxations=relaxations,
                                user_defined_options=self.user_defined_options)
             # Those lists are shared by all interpreters. That means that
             # even if the subproject fails, any modification that the subproject