diff --git a/nemo/collections/asr/parts/utils/transcribe_utils.py b/nemo/collections/asr/parts/utils/transcribe_utils.py
index 9c576ce3c093..e7a3bd1e1a0f 100644
--- a/nemo/collections/asr/parts/utils/transcribe_utils.py
+++ b/nemo/collections/asr/parts/utils/transcribe_utils.py
@@ -18,7 +18,7 @@
 from dataclasses import dataclass
 from pathlib import Path
 from tempfile import NamedTemporaryFile
-from typing import List, Optional, Tuple, Union
+from typing import Dict, List, Optional, Tuple, Union
 
 import torch
 from omegaconf import DictConfig
@@ -106,9 +106,9 @@ def get_buffered_pred_feat_rnnt(
     delay: int,
     model_stride_in_secs: int,
     batch_size: int,
-    manifest: str = None,
-    filepaths: List[list] = None,
-    target_lang_id: str = None,
+    manifest: Optional[str] = None,
+    filepaths: Optional[List[list]] = None,
+    target_lang_id: Optional[str] = None,
     accelerator: Optional[str] = 'cpu',
 ) -> List[rnnt_utils.Hypothesis]:
     """
@@ -219,8 +219,8 @@ def get_buffered_pred_feat_multitaskAED(
     preprocessor_cfg: DictConfig,
     model_stride_in_secs: int,
     device: Union[List[int], int],
-    manifest: str = None,
-    filepaths: List[list] = None,
+    manifest: Optional[str] = None,
+    filepaths: Optional[List[list]] = None,
     delay: float = 0.0,
     timestamps: bool = False,
 ) -> List[rnnt_utils.Hypothesis]:
@@ -390,7 +390,7 @@ def read_and_maybe_sort_manifest(path: str, try_sort: bool = False) -> List[dict
     return items
 
 
-def restore_transcription_order(manifest_path: str, transcriptions: list) -> list:
+def restore_transcription_order(manifest_path: str, transcriptions: List) -> Union[List, Tuple]:
     with open(manifest_path, encoding='utf-8') as f:
         items = [(idx, json.loads(l)) for idx, l in enumerate(f) if l.strip() != ""]
     if not all("duration" in item[1] and item[1]["duration"] is not None for item in items):
@@ -422,7 +422,7 @@ def compute_output_filename(cfg: DictConfig, model_name: str) -> DictConfig:
     return cfg
 
 
-def normalize_timestamp_output(timestamps: dict):
+def normalize_timestamp_output(timestamps: Dict) -> Dict:
     """
     Normalize the dictionary of timestamp values to JSON serializable values.
     Expects the following keys to exist -
@@ -447,7 +447,7 @@ def write_transcription(
     transcriptions: Union[List[rnnt_utils.Hypothesis], List[List[rnnt_utils.Hypothesis]], List[str]],
     cfg: DictConfig,
     model_name: str,
-    filepaths: List[str] = None,
+    filepaths: Optional[List[str]] = None,
     compute_langs: bool = False,
     timestamps: bool = False,
 ) -> Tuple[str, str]:
@@ -549,7 +549,7 @@ def compute_metrics_per_sample(
     hypothesis_field: str = "pred_text",
     metrics: List[str] = ["wer"],
     punctuation_marks: List[str] = [".", ",", "?"],
-    output_manifest_path: str = None,
+    output_manifest_path: Optional[str] = None,
 ) -> dict:
     '''
     Computes metrics per sample for given manifest
@@ -637,7 +637,7 @@ def compute_metrics_per_sample(
 
 
 class PunctuationCapitalization:
-    def __init__(self, punctuation_marks: str):
+    def __init__(self, punctuation_marks: str) -> None:
         """
         Class for text processing with punctuation and capitalization. Can be used with class TextProcessingConfig.