diff --git a/generator/src/telethon_generator/_impl/codegen/generator.py b/generator/src/telethon_generator/_impl/codegen/generator.py
index d06146b3..ff13680a 100644
--- a/generator/src/telethon_generator/_impl/codegen/generator.py
+++ b/generator/src/telethon_generator/_impl/codegen/generator.py
@@ -94,7 +94,7 @@ def generate(fs: FakeFs, tl: ParsedTl) -> None:
 
         if type_path not in fs:
             writer.write("import struct")
-            writer.write("from typing import List, Optional, Self")
+            writer.write("from typing import List, Optional, Self, Sequence")
             writer.write("from .. import abcs")
             writer.write("from ..core import Reader, Serializable, serialize_bytes_to")
 
@@ -118,7 +118,8 @@ def generate(fs: FakeFs, tl: ParsedTl) -> None:
         #   def __init__()
         if property_params:
             params = "".join(
-                f", {p.name}: {param_type_fmt(p.ty)}" for p in property_params
+                f", {p.name}: {param_type_fmt(p.ty, immutable=False)}"
+                for p in property_params
             )
             writer.write(f"  def __init__(_s, *{params}) -> None:")
             for p in property_params:
@@ -158,15 +159,20 @@ def generate(fs: FakeFs, tl: ParsedTl) -> None:
 
         if function_path not in fs:
             writer.write("import struct")
-            writer.write("from typing import List, Optional, Self")
+            writer.write("from typing import List, Optional, Self, Sequence")
             writer.write("from .. import abcs")
             writer.write("from ..core import Request, serialize_bytes_to")
 
         #   def name(params, ...)
         required_params = [p for p in functiondef.params if not is_computed(p.ty)]
-        params = "".join(f", {p.name}: {param_type_fmt(p.ty)}" for p in required_params)
+        params = "".join(
+            f", {p.name}: {param_type_fmt(p.ty, immutable=True)}"
+            for p in required_params
+        )
         star = "*" if params else ""
-        return_ty = param_type_fmt(NormalParameter(ty=functiondef.ty, flag=None))
+        return_ty = param_type_fmt(
+            NormalParameter(ty=functiondef.ty, flag=None), immutable=False
+        )
         writer.write(
             f"def {to_method_name(functiondef.name)}({star}{params}) -> Request[{return_ty}]:"
         )
diff --git a/generator/src/telethon_generator/_impl/codegen/serde/common.py b/generator/src/telethon_generator/_impl/codegen/serde/common.py
index adcbe714..e96fca74 100644
--- a/generator/src/telethon_generator/_impl/codegen/serde/common.py
+++ b/generator/src/telethon_generator/_impl/codegen/serde/common.py
@@ -86,7 +86,7 @@ def inner_type_fmt(ty: Type) -> str:
         return f"abcs.{ns}{to_class_name(ty.name)}"
 
 
-def param_type_fmt(ty: BaseParameter) -> str:
+def param_type_fmt(ty: BaseParameter, *, immutable: bool) -> str:
     if isinstance(ty, FlagsParameter):
         return "int"
     elif not isinstance(ty, NormalParameter):
@@ -104,7 +104,10 @@ def param_type_fmt(ty: BaseParameter) -> str:
     res = "bytes" if inner_ty.name == "Object" else inner_type_fmt(inner_ty)
 
     if ty.ty.generic_arg:
-        res = f"List[{res}]"
+        if immutable:
+            res = f"Sequence[{res}]"
+        else:
+            res = f"List[{res}]"
 
     if ty.flag and ty.ty.name != "true":
         res = f"Optional[{res}]"