diff --git a/worlds/alttp/Rom.py b/worlds/alttp/Rom.py
index 05460e0f..05113514 100644
--- a/worlds/alttp/Rom.py
+++ b/worlds/alttp/Rom.py
@@ -18,7 +18,7 @@ import subprocess
 import threading
 import concurrent.futures
 import bsdiff4
-from typing import Optional, List
+from typing import Collection, Optional, List, SupportsIndex
 
 from BaseClasses import CollectionState, Region, Location, MultiWorld
 from Utils import local_path, user_path, int16_as_bytes, int32_as_bytes, snes_to_pc, is_frozen, parse_yaml, read_snes_rom
@@ -52,7 +52,7 @@ except:
 enemizer_logger = logging.getLogger("Enemizer")
 
 
-class LocalRom(object):
+class LocalRom:
 
     def __init__(self, file, patch=True, vanillaRom=None, name=None, hash=None):
         self.name = name
@@ -71,13 +71,13 @@ class LocalRom(object):
     def read_byte(self, address: int) -> int:
         return self.buffer[address]
 
-    def read_bytes(self, startaddress: int, length: int) -> bytes:
+    def read_bytes(self, startaddress: int, length: int) -> bytearray:
         return self.buffer[startaddress:startaddress + length]
 
     def write_byte(self, address: int, value: int):
         self.buffer[address] = value
 
-    def write_bytes(self, startaddress: int, values):
+    def write_bytes(self, startaddress: int, values: Collection[SupportsIndex]) -> None:
         self.buffer[startaddress:startaddress + len(values)] = values
 
     def encrypt_range(self, startaddress: int, length: int, key: bytes):
diff --git a/worlds/dkc3/Rom.py b/worlds/dkc3/Rom.py
index efe8033d..0dc722a7 100644
--- a/worlds/dkc3/Rom.py
+++ b/worlds/dkc3/Rom.py
@@ -434,7 +434,7 @@ level_music_ids = [
     0x21,
 ]
 
-class LocalRom(object):
+class LocalRom:
 
     def __init__(self, file, patch=True, vanillaRom=None, name=None, hash=None):
         self.name = name
@@ -457,7 +457,7 @@ class LocalRom(object):
     def read_byte(self, address: int) -> int:
         return self.buffer[address]
 
-    def read_bytes(self, startaddress: int, length: int) -> bytes:
+    def read_bytes(self, startaddress: int, length: int) -> bytearray:
         return self.buffer[startaddress:startaddress + length]
 
     def write_byte(self, address: int, value: int):
diff --git a/worlds/smw/Rom.py b/worlds/smw/Rom.py
index 36078d46..ff3b5c31 100644
--- a/worlds/smw/Rom.py
+++ b/worlds/smw/Rom.py
@@ -83,7 +83,7 @@ class LocalRom:
     def read_byte(self, address: int) -> int:
         return self.buffer[address]
 
-    def read_bytes(self, startaddress: int, length: int) -> bytes:
+    def read_bytes(self, startaddress: int, length: int) -> bytearray:
         return self.buffer[startaddress:startaddress + length]
 
     def write_byte(self, address: int, value: int):
diff --git a/worlds/yoshisisland/Rom.py b/worlds/yoshisisland/Rom.py
index fa3006af..0943ba82 100644
--- a/worlds/yoshisisland/Rom.py
+++ b/worlds/yoshisisland/Rom.py
@@ -3,7 +3,7 @@ import os
 import Utils
 from worlds.Files import APDeltaPatch
 from settings import get_settings
-from typing import TYPE_CHECKING
+from typing import TYPE_CHECKING, Collection, SupportsIndex
 
 from .Options import YoshiColors, BowserDoor, PlayerGoal, MinigameChecks
 
@@ -396,7 +396,7 @@ location_table = {
     0x30510B: [0x14B2, 4]
 }
 
-class LocalRom(object):
+class LocalRom:
 
     def __init__(self, file: str) -> None:
         self.name = None
@@ -413,13 +413,13 @@ class LocalRom(object):
     def read_byte(self, address: int) -> int:
         return self.buffer[address]
 
-    def read_bytes(self, startaddress: int, length: int) -> bytes:
+    def read_bytes(self, startaddress: int, length: int) -> bytearray:
         return self.buffer[startaddress:startaddress + length]
 
     def write_byte(self, address: int, value: int) -> None:
         self.buffer[address] = value
 
-    def write_bytes(self, startaddress: int, values: bytearray) -> None:
+    def write_bytes(self, startaddress: int, values: Collection[SupportsIndex]) -> None:
         self.buffer[startaddress:startaddress + len(values)] = values
 
     def write_to_file(self, file: str) -> None: