diff --git a/mesonbuild/ast/interpreter.py b/mesonbuild/ast/interpreter.py
index d3afb4de3006..3ec6c85a070b 100644
--- a/mesonbuild/ast/interpreter.py
+++ b/mesonbuild/ast/interpreter.py
@@ -494,14 +494,12 @@ def func_files(self, node: BaseNode, args: T.List[TYPE_var], kwargs: T.Dict[str,
     def get_cur_value_if_defined(self, var_name: str) -> T.Union[BaseNode, UnknownValue, UndefinedVariable]:
         if var_name in self.predefined_vars:
             return self.predefined_vars[var_name]
-        ret: T.Union[BaseNode, UnknownValue, UndefinedVariable] = UndefinedVariable()
         for nesting, value in reversed(self.cur_assignments[var_name]):
             if len(self.nesting) >= len(nesting) and self.nesting[:len(nesting)] == nesting:
-                ret = value
-                break
-        if isinstance(ret, UndefinedVariable) and self.tainted:
+                return value
+        if self.tainted:
             return UnknownValue()
-        return ret
+        return UndefinedVariable()
 
     def get_cur_value(self, var_name: str) -> T.Union[BaseNode, UnknownValue]:
         ret = self.get_cur_value_if_defined(var_name)