diff --git a/machine/translation/huggingface/hugging_face_nmt_engine.py b/machine/translation/huggingface/hugging_face_nmt_engine.py
index 9d43b28..4da476c 100644
--- a/machine/translation/huggingface/hugging_face_nmt_engine.py
+++ b/machine/translation/huggingface/hugging_face_nmt_engine.py
@@ -55,8 +55,8 @@ def __init__(
         self._tokenizer = AutoTokenizer.from_pretrained(self._model.name_or_path, use_fast=True)
         if isinstance(self._tokenizer, (NllbTokenizer, NllbTokenizerFast)):
             self._mpn = MosesPunctNormalizer()
-            self._mpn.substitutions = [
-                (str(re.compile(r)), sub)
+            self._mpn.substitutions = [  # type: ignore
+                (re.compile(r), sub)
                 for r, sub in self._mpn.substitutions
                 if isinstance(r, str) and isinstance(sub, str)
             ]
diff --git a/machine/translation/huggingface/hugging_face_nmt_model_trainer.py b/machine/translation/huggingface/hugging_face_nmt_model_trainer.py
index f15ba4e..1192243 100644
--- a/machine/translation/huggingface/hugging_face_nmt_model_trainer.py
+++ b/machine/translation/huggingface/hugging_face_nmt_model_trainer.py
@@ -100,10 +100,8 @@ def __init__(
         self._add_unk_src_tokens = add_unk_src_tokens
         self._add_unk_tgt_tokens = add_unk_tgt_tokens
         self._mpn = MosesPunctNormalizer()
-        self._mpn.substitutions = [
-            (str(re.compile(r)), sub)
-            for r, sub in self._mpn.substitutions
-            if isinstance(r, str) and isinstance(sub, str)
+        self._mpn.substitutions = [  # type: ignore
+            (re.compile(r), sub) for r, sub in self._mpn.substitutions if isinstance(r, str) and isinstance(sub, str)
         ]
         self._stats = TrainStats()