diff --git a/natsapi/_compat.py b/natsapi/_compat.py
index e8f1d82..0395b13 100644
--- a/natsapi/_compat.py
+++ b/natsapi/_compat.py
@@ -235,3 +235,15 @@ def sort(self, value: JsonSchemaValue, *args) -> JsonSchemaValue:
         https://docs.pydantic.dev/latest/concepts/json_schema/#json-schema-sorting
         """
         return value
+
+    def nullable_schema(self, schema: JsonSchemaValue) -> JsonSchemaValue:
+        """
+        Override nullable schema generation to flatten optional types.
+        Instead of generating anyOf with [type, null], just return the type.
+        """
+        if PYDANTIC_V2:
+            # Extract the inner schema and generate it without the null variant
+            inner_schema = schema.get("schema")
+            if inner_schema:
+                return self.generate_inner(inner_schema)
+        return super().nullable_schema(schema)
diff --git a/shell.nix b/shell.nix
index 0703d57..309bf2e 100644
--- a/shell.nix
+++ b/shell.nix
@@ -9,21 +9,9 @@ in pkgs.mkShell {
 
     packages = with pkgs; [
         python311
-
         ruff
         rustc
         cargo
-
-        (poetry.override { python3 = python311; })
-
-        (python311.withPackages (p: with p; [
-            pip
-            python-lsp-server
-            pynvim
-            pyls-isort
-            python-lsp-black
-        ]))
-
     ];
 
     env.LD_LIBRARY_PATH = pkgs.lib.makeLibraryPath [
diff --git a/tests/asyncapi/test_generation.py b/tests/asyncapi/test_generation.py
index 9d68cba..395ba74 100644
--- a/tests/asyncapi/test_generation.py
+++ b/tests/asyncapi/test_generation.py
@@ -1,4 +1,5 @@
-from typing import Any, Union
+import sys
+from typing import Any, Optional, Union
 from uuid import uuid4
 
 import pytest
@@ -126,6 +127,51 @@ def test_generate_schema_w_external_docs_should_generate():
     assert schema["externalDocs"] == external_docs.dict()
 
 
+@pytest.mark.skipif(sys.version_info < (3, 10), reason="Requires Python 3.10+ for union syntax")
+async def test_optional_types_are_generated_correctly(app: NatsAPI):
+    class User(BaseModel):
+        name: str
+        mandatory_property_1: str
+        optional_property_1: str | None
+        optional_property_2: Optional[str]
+        optional_property_3: Optional[str] = None
+        optional_property_4: Optional[str] | None = None
+        optional_property_5: str | None = None
+        optional_property_6: str = None
+        optional_property_7: str | int
+
+    user_router = SubjectRouter(prefix="v1", tags=["users"], deprecated=True)
+
+    @user_router.request(
+        "users.CREATE",
+        result=User,
+        description="Creates user that can be used throughout the app",
+        tags=["auth"],
+        suggested_timeout=0.5,
+    )
+    def create_base_user(app, user: User):
+        return {"id": uuid4(), "name": user.name}
+
+    app.include_router(user_router)
+    app.generate_asyncapi()
+    schema = app.asyncapi_schema
+
+    assert schema["components"]["schemas"]["User"]["properties"]["mandatory_property_1"]["type"] == "string"
+    assert schema["components"]["schemas"]["User"]["properties"]["optional_property_1"]["type"] == "string"
+    assert schema["components"]["schemas"]["User"]["properties"]["optional_property_2"]["type"] == "string"
+    assert schema["components"]["schemas"]["User"]["properties"]["optional_property_3"]["type"] == "string"
+    assert schema["components"]["schemas"]["User"]["properties"]["optional_property_4"]["type"] == "string"
+    assert schema["components"]["schemas"]["User"]["properties"]["optional_property_5"]["type"] == "string"
+    assert schema["components"]["schemas"]["User"]["properties"]["optional_property_6"]["type"] == "string"
+    assert schema["components"]["schemas"]["User"]["properties"]["optional_property_7"]["anyOf"] == [
+        {"type": "string"},
+        {"type": "integer"},
+    ]
+
+    schema_from_request = (await app.nc.request("natsapi.development.schema.RETRIEVE", {})).result
+    assert schema_from_request == schema
+
+
 async def test_generate_shema_w_requests_should_generate(app: NatsAPI):
     class BaseUser(BaseModel):
         email: str = Field(..., description="Unique email of user", example="foo@bar.com")