diff --git a/byron/classes/evaluator.py b/byron/classes/evaluator.py
index 853d139..7a6472e 100644
--- a/byron/classes/evaluator.py
+++ b/byron/classes/evaluator.py
@@ -319,6 +319,7 @@ class MakefileEvaluator(EvaluatorABC):
     _make_flags: tuple[str]
     _makefile: str
     _required_files: tuple[str]
+    _stdout_cleaner: Callable[[str], Sequence[float] | float] | None
     _byron_base_dir: str
     _timeout: int | None
 
@@ -330,6 +331,7 @@ def __init__(
         make_command='make',
         make_flags: Sequence[str] = ('-s',),
         makefile='Makefile',
+        stdout_cleaner: Callable[[str], Sequence[float] | float] | None = None,
         timeout: int | None = 60,
         **kwargs,
     ) -> None:
@@ -359,6 +361,7 @@ def __init__(
         self._required_files = tuple(required_files)
         self._timeout = timeout
         self._byron_base_dir = os.getcwd()
+        self._stdout_cleaner = stdout_cleaner
 
         for f in self._required_files:
             if not os.path.exists(f):
@@ -419,9 +422,12 @@ def evaluate_population(self, population: Population) -> None:
                 if result is None:
                     raise RuntimeError(f"Thread failed (returned None)")
                 else:
-                    value = [float(r) for r in result.stdout.split()]
-                    if len(value) == 1:
-                        value = value[0]
+                    if self._stdout_cleaner is None:
+                        value = [float(r) if '.' in r else int(r) for r in result.stdout.split()]
+                        if len(value) == 1:
+                            value = value[0]
+                    else:
+                        value = self._stdout_cleaner(result.stdout)
                     fitness = make_fitness(value)
                     population[i].fitness = fitness