diff --git a/inno_setup.iss b/inno_setup.iss
index 529a96a33ac6..4b37279e8de0 100644
--- a/inno_setup.iss
+++ b/inno_setup.iss
@@ -169,6 +169,11 @@ Root: HKCR; Subkey: "{#MyAppName}pkmnepatch";                     ValueData: "Ar
 Root: HKCR; Subkey: "{#MyAppName}pkmnepatch\DefaultIcon";         ValueData: "{app}\ArchipelagoBizHawkClient.exe,0";                                          ValueType: string; ValueName: "";
 Root: HKCR; Subkey: "{#MyAppName}pkmnepatch\shell\open\command";  ValueData: """{app}\ArchipelagoBizHawkClient.exe"" ""%1""";                                 ValueType: string; ValueName: "";
 
+Root: HKCR; Subkey: ".apmlss";                                 ValueData: "{#MyAppName}mlsspatch";                               Flags: uninsdeletevalue; ValueType: string; ValueName: "";
+Root: HKCR; Subkey: "{#MyAppName}mlsspatch";                     ValueData: "Archipelago Mario & Luigi Superstar Saga Patch";                    Flags: uninsdeletekey;   ValueType: string; ValueName: "";
+Root: HKCR; Subkey: "{#MyAppName}mlsspatch\DefaultIcon";         ValueData: "{app}\ArchipelagoBizHawkClient.exe,0";                                          ValueType: string; ValueName: "";
+Root: HKCR; Subkey: "{#MyAppName}mlsspatch\shell\open\command";  ValueData: """{app}\ArchipelagoBizHawkClient.exe"" ""%1""";                                 ValueType: string; ValueName: "";
+
 Root: HKCR; Subkey: ".apcv64";                                 ValueData: "{#MyAppName}cv64patch";                               Flags: uninsdeletevalue; ValueType: string; ValueName: "";
 Root: HKCR; Subkey: "{#MyAppName}cv64patch";                     ValueData: "Archipelago Castlevania 64 Patch";                    Flags: uninsdeletekey;   ValueType: string; ValueName: "";
 Root: HKCR; Subkey: "{#MyAppName}cv64patch\DefaultIcon";         ValueData: "{app}\ArchipelagoBizHawkClient.exe,0";                                          ValueType: string; ValueName: "";
diff --git a/worlds/mlss/Client.py b/worlds/mlss/Client.py
index 322f243ceb00..a1cd43afbae8 100644
--- a/worlds/mlss/Client.py
+++ b/worlds/mlss/Client.py
@@ -47,19 +47,10 @@ async def validate_rom(self, ctx: "BizHawkClientContext") -> bool:
             # Check ROM name/patch version
             rom_name_bytes = await bizhawk.read(ctx.bizhawk_ctx, [(0xA0, 14, "ROM")])
             rom_name = bytes([byte for byte in rom_name_bytes[0] if byte != 0]).decode("UTF-8")
-            if not rom_name.startswith("MARIO&LUIGIU"):
-                return False
-            if rom_name == "MARIO&LUIGIUA8":
-                logger.info(
-                    "ERROR: You appear to be running an unpatched version of Mario & Luigi Superstar Saga. "
-                    "You need to generate a patch file and use it to create a patched ROM."
-                )
-                return False
-            if rom_name != "MARIO&LUIGIUAP":
+            if not rom_name.startswith("MARIO&LUIGIUA8"):
                 logger.info(
-                    "ERROR: The patch file used to create this ROM is not compatible with "
-                    "this client. Double check your client version against the version being "
-                    "used by the generator."
+                    "ERROR: You have opened a game that is not Mario & Luigi Superstar Saga. "
+                    "Please make sure you are opening the correct ROM."
                 )
                 return False
         except UnicodeDecodeError:
diff --git a/worlds/mlss/Regions.py b/worlds/mlss/Regions.py
index be1c5d1063ae..992e99e2c7f7 100644
--- a/worlds/mlss/Regions.py
+++ b/worlds/mlss/Regions.py
@@ -299,7 +299,7 @@ def connect(
     target: str,
     rule: typing.Optional[typing.Callable] = None,
     reach: typing.Optional[bool] = False,
-) -> Entrance | None:
+) -> typing.Optional[Entrance]:
     source_region = world.multiworld.get_region(source, world.player)
     target_region = world.multiworld.get_region(target, world.player)
 
@@ -317,7 +317,4 @@ def connect(
 
     source_region.exits.append(connection)
     connection.connect(target_region)
-    if reach:
-        return connection
-    else:
-        return None
+    return connection if reach else None
diff --git a/worlds/mlss/Rom.py b/worlds/mlss/Rom.py
index 1b8a182509ae..08921500dacb 100644
--- a/worlds/mlss/Rom.py
+++ b/worlds/mlss/Rom.py
@@ -272,9 +272,6 @@ def write_tokens(world: "MLSSWorld", patch: MLSSProcedurePatch) -> None:
     # Bake seed name into ROM
     patch.write_token(APTokenTypes.WRITE, 0xDF00A0, world.multiworld.seed_name.encode("UTF-8"))
 
-    # Bake patch into header
-    patch.write_token(APTokenTypes.WRITE, 0xAD, "P".encode("UTF-8"))
-
     # Intro Skip
     patch.write_token(
         APTokenTypes.WRITE,
diff --git a/worlds/mlss/data/basepatch.bsdiff b/worlds/mlss/data/basepatch.bsdiff
index 45ed6a6b724f..156d28f346e8 100644
Binary files a/worlds/mlss/data/basepatch.bsdiff and b/worlds/mlss/data/basepatch.bsdiff differ