diff --git a/mypy.ini b/mypy.ini
index c06d521..f7b2f0b 100644
--- a/mypy.ini
+++ b/mypy.ini
@@ -8,6 +8,6 @@ warn_unused_configs = True
 #disallow_any_explicit = True
 #disallow_any_generics = True
 #disallow_subclassing_any = True
-#disallow_untyped_calls = True
+disallow_untyped_calls = True
 disallow_untyped_defs = True
 disallow_incomplete_defs = True
diff --git a/src/edge_tts/list_voices.py b/src/edge_tts/list_voices.py
index 2f18cc4..9793b5d 100644
--- a/src/edge_tts/list_voices.py
+++ b/src/edge_tts/list_voices.py
@@ -3,7 +3,7 @@ list_voices package for edge_tts.
 """
 
 import json
-from typing import Any, Optional
+from typing import Any, Dict, List, Optional
 
 import aiohttp
 
@@ -47,8 +47,12 @@ class VoicesManager:
     A class to find the correct voice based on their attributes.
     """
 
+    def __init__(self) -> None:
+        self.voices: List[Dict[str, Any]] = []
+        self.called_create: bool = False
+
     @classmethod
-    async def create(cls): # type: ignore
+    async def create(cls: Any) -> "VoicesManager":
         """
         Creates a VoicesManager object and populates it with all available voices.
         """
@@ -58,14 +62,19 @@ class VoicesManager:
             {**voice, **{"Language": voice["Locale"].split("-")[0]}}
             for voice in self.voices
         ]
+        self.called_create = True
         return self
 
-    def find(self, **kwargs: Any) -> list[dict[str, Any]]:
+    def find(self, **kwargs: Any) -> List[Dict[str, Any]]:
         """
         Finds all matching voices based on the provided attributes.
         """
+        if not self.called_create:
+            raise RuntimeError(
+                "VoicesManager.find() called before VoicesManager.create()"
+            )
 
         matching_voices = [
-            voice for voice in self.voices if kwargs.items() <= voice.items() # type: ignore
+            voice for voice in self.voices if kwargs.items() <= voice.items()
         ]
         return matching_voices
diff --git a/src/edge_tts/submaker.py b/src/edge_tts/submaker.py
index 373ca96..03a04db 100644
--- a/src/edge_tts/submaker.py
+++ b/src/edge_tts/submaker.py
@@ -78,7 +78,9 @@ class SubMaker:
             data = "WEBVTT\r\n\r\n"
             for offset, subs in zip(self.offset, self.subs):
                 subs = unescape(subs)
-                split_subs: List[str] = [subs[i : i + 79] for i in range(0, len(subs), 79)]
+                split_subs: List[str] = [
+                    subs[i : i + 79] for i in range(0, len(subs), 79)
+                ]
 
                 for i in range(len(split_subs) - 1):
                     sub = split_subs[i]
diff --git a/src/edge_tts/util.py b/src/edge_tts/util.py
index 132896c..638a5dc 100644
--- a/src/edge_tts/util.py
+++ b/src/edge_tts/util.py
@@ -5,8 +5,8 @@ Main package.
 
 import argparse
 import asyncio
-from io import BufferedWriter
 import sys
+from io import BufferedWriter
 from typing import Any
 
 from edge_tts import Communicate, SubMaker, list_voices
@@ -45,7 +45,7 @@ async def _run_tts(args: Any) -> None:
                 if isinstance(media_file, BufferedWriter):
                     media_file.write(data["data"])
                 else:
-                    sys.stdout.buffer.write(data["data"])                    
+                    sys.stdout.buffer.write(data["data"])
             elif data["type"] == "WordBoundary":
                 subs.create_sub((data["offset"], data["duration"]), data["text"])