diff --git a/tests/test_additional_responses.py b/tests/test_additional_responses.py
new file mode 100644
index 000000000..b7bfae224
--- /dev/null
+++ b/tests/test_additional_responses.py
@@ -0,0 +1,594 @@
+from fastapi import FastAPI
+from fastapi.openapi.models import AdditionalResponse
+from pydantic import BaseModel
+from starlette.responses import JSONResponse
+from starlette.testclient import TestClient
+
+app = FastAPI()
+
+
+class Item(BaseModel):
+    name: str
+    price: float = None
+
+
+class Response400(BaseModel):
+    '''HTTP 4xx Response Schema'''
+    title: str
+    detail: str
+    error_code: int # functional error ref
+
+
+response_403 = AdditionalResponse(
+    status_code = 403,
+    description = 'Forbidden',
+    models = [
+        Response400,
+    ],
+)
+
+additional_responses = [
+    response_403,
+]
+
+@app.api_route(
+    "/items/{item_id}",
+    methods=["GET"],
+    additional_responses=additional_responses,
+)
+def get_items(item_id: str):
+    return {"item_id": item_id}
+
+
+def get_not_decorated(item_id: str):
+    return {"item_id": item_id}
+
+
+app.add_api_route(
+    "/items-not-decorated/{item_id}",
+    get_not_decorated,
+    additional_responses=additional_responses,
+)
+
+
+@app.delete(
+    "/items/{item_id}",
+    additional_responses=additional_responses,
+)
+def delete_item(item_id: str, item: Item):
+    return {"item_id": item_id, "item": item}
+
+
+@app.head(
+    "/items/{item_id}",
+    additional_responses=additional_responses,
+)
+def head_item(item_id: str):
+    return JSONResponse(headers={"x-fastapi-item-id": item_id})
+
+
+@app.options(
+    "/items/{item_id}",
+    additional_responses=additional_responses,
+)
+def options_item(item_id: str):
+    return JSONResponse(headers={"x-fastapi-item-id": item_id})
+
+
+@app.patch(
+    "/items/{item_id}",
+    additional_responses=additional_responses,
+)
+def patch_item(item_id: str, item: Item):
+    return {"item_id": item_id, "item": item}
+
+
+@app.trace(
+    "/items/{item_id}",
+    additional_responses=additional_responses,
+)
+def trace_item(item_id: str):
+    return JSONResponse(media_type="message/http")
+
+
+client = TestClient(app)
+
+openapi_schema = {
+    "openapi": "3.0.2",
+    "info": {
+        "title": "Fast API",
+        "version": "0.1.0"
+    },
+    "paths": {
+        "/items/{item_id}": {
+            "get": {
+                "responses": {
+                    "200": {
+                        "description": "Successful Response",
+                        "content": {
+                            "application/json": {
+                                "schema": {}
+                            }
+                        },
+                    },
+                    "403": {
+                        "description": "Forbidden",
+                        "content": {
+                            "application/json": {
+                                "schema": {
+                                    "$ref": "#/components/schemas/Response400"
+                                }
+                            }
+                        },
+                    },
+                    "422": {
+                        "description": "Validation Error",
+                        "content": {
+                            "application/json": {
+                                "schema": {
+                                    "$ref":
+                                    "#/components/schemas/HTTPValidationError"
+                                }
+                            }
+                        },
+                    },
+                },
+                "summary":
+                "Get Items Get",
+                "operationId":
+                "get_items_items__item_id__get",
+                "parameters": [{
+                    "required": True,
+                    "schema": {
+                        "title": "Item_Id",
+                        "type": "string"
+                    },
+                    "name": "item_id",
+                    "in": "path",
+                }],
+            },
+            "delete": {
+                "responses": {
+                    "200": {
+                        "description": "Successful Response",
+                        "content": {
+                            "application/json": {
+                                "schema": {}
+                            }
+                        },
+                    },
+                    "403": {
+                        "description": "Forbidden",
+                        "content": {
+                            "application/json": {
+                                "schema": {
+                                    "$ref": "#/components/schemas/Response400"
+                                }
+                            }
+                        },
+                    },
+                    "422": {
+                        "description": "Validation Error",
+                        "content": {
+                            "application/json": {
+                                "schema": {
+                                    "$ref":
+                                    "#/components/schemas/HTTPValidationError"
+                                }
+                            }
+                        },
+                    },
+                },
+                "summary":
+                "Delete Item Delete",
+                "operationId":
+                "delete_item_items__item_id__delete",
+                "parameters": [{
+                    "required": True,
+                    "schema": {
+                        "title": "Item_Id",
+                        "type": "string"
+                    },
+                    "name": "item_id",
+                    "in": "path",
+                }],
+                "requestBody": {
+                    "content": {
+                        "application/json": {
+                            "schema": {
+                                "$ref": "#/components/schemas/Item"
+                            }
+                        }
+                    },
+                    "required": True,
+                },
+            },
+            "options": {
+                "responses": {
+                    "200": {
+                        "description": "Successful Response",
+                        "content": {
+                            "application/json": {
+                                "schema": {}
+                            }
+                        },
+                    },
+                    "403": {
+                        "description": "Forbidden",
+                        "content": {
+                            "application/json": {
+                                "schema": {
+                                    "$ref": "#/components/schemas/Response400"
+                                }
+                            }
+                        },
+                    },
+                    "403": {
+                        "description": "Forbidden",
+                        "content": {
+                            "application/json": {
+                                "schema": {
+                                    "$ref": "#/components/schemas/Response400"
+                                }
+                            }
+                        },
+                    },
+                    "422": {
+                        "description": "Validation Error",
+                        "content": {
+                            "application/json": {
+                                "schema": {
+                                    "$ref":
+                                    "#/components/schemas/HTTPValidationError"
+                                }
+                            }
+                        },
+                    },
+                },
+                "summary":
+                "Options Item Options",
+                "operationId":
+                "options_item_items__item_id__options",
+                "parameters": [{
+                    "required": True,
+                    "schema": {
+                        "title": "Item_Id",
+                        "type": "string"
+                    },
+                    "name": "item_id",
+                    "in": "path",
+                }],
+            },
+            "head": {
+                "responses": {
+                    "200": {
+                        "description": "Successful Response",
+                        "content": {
+                            "application/json": {
+                                "schema": {}
+                            }
+                        },
+                    },
+                    "403": {
+                        "description": "Forbidden",
+                        "content": {
+                            "application/json": {
+                                "schema": {
+                                    "$ref": "#/components/schemas/Response400"
+                                }
+                            }
+                        },
+                    },
+                    "422": {
+                        "description": "Validation Error",
+                        "content": {
+                            "application/json": {
+                                "schema": {
+                                    "$ref":
+                                    "#/components/schemas/HTTPValidationError"
+                                }
+                            }
+                        },
+                    },
+                },
+                "summary":
+                "Head Item Head",
+                "operationId":
+                "head_item_items__item_id__head",
+                "parameters": [{
+                    "required": True,
+                    "schema": {
+                        "title": "Item_Id",
+                        "type": "string"
+                    },
+                    "name": "item_id",
+                    "in": "path",
+                }],
+            },
+            "patch": {
+                "responses": {
+                    "200": {
+                        "description": "Successful Response",
+                        "content": {
+                            "application/json": {
+                                "schema": {}
+                            }
+                        },
+                    },
+                    "403": {
+                        "description": "Forbidden",
+                        "content": {
+                            "application/json": {
+                                "schema": {
+                                    "$ref": "#/components/schemas/Response400"
+                                }
+                            }
+                        },
+                    },
+                    "422": {
+                        "description": "Validation Error",
+                        "content": {
+                            "application/json": {
+                                "schema": {
+                                    "$ref":
+                                    "#/components/schemas/HTTPValidationError"
+                                }
+                            }
+                        },
+                    },
+                },
+                "summary":
+                "Patch Item Patch",
+                "operationId":
+                "patch_item_items__item_id__patch",
+                "parameters": [{
+                    "required": True,
+                    "schema": {
+                        "title": "Item_Id",
+                        "type": "string"
+                    },
+                    "name": "item_id",
+                    "in": "path",
+                }],
+                "requestBody": {
+                    "content": {
+                        "application/json": {
+                            "schema": {
+                                "$ref": "#/components/schemas/Item"
+                            }
+                        }
+                    },
+                    "required": True,
+                },
+            },
+            "trace": {
+                "responses": {
+                    "200": {
+                        "description": "Successful Response",
+                        "content": {
+                            "application/json": {
+                                "schema": {}
+                            }
+                        },
+                    },
+                    "403": {
+                        "description": "Forbidden",
+                        "content": {
+                            "application/json": {
+                                "schema": {
+                                    "$ref": "#/components/schemas/Response400"
+                                }
+                            }
+                        },
+                    },
+                    "422": {
+                        "description": "Validation Error",
+                        "content": {
+                            "application/json": {
+                                "schema": {
+                                    "$ref":
+                                    "#/components/schemas/HTTPValidationError"
+                                }
+                            }
+                        },
+                    },
+                },
+                "summary":
+                "Trace Item Trace",
+                "operationId":
+                "trace_item_items__item_id__trace",
+                "parameters": [{
+                    "required": True,
+                    "schema": {
+                        "title": "Item_Id",
+                        "type": "string"
+                    },
+                    "name": "item_id",
+                    "in": "path",
+                }],
+            },
+        },
+        "/items-not-decorated/{item_id}": {
+            "get": {
+                "responses": {
+                    "200": {
+                        "description": "Successful Response",
+                        "content": {
+                            "application/json": {
+                                "schema": {}
+                            }
+                        },
+                    },
+                    "403": {
+                        "description": "Forbidden",
+                        "content": {
+                            "application/json": {
+                                "schema": {
+                                    "$ref": "#/components/schemas/Response400"
+                                }
+                            }
+                        },
+                    },
+                    "422": {
+                        "description": "Validation Error",
+                        "content": {
+                            "application/json": {
+                                "schema": {
+                                    "$ref":
+                                    "#/components/schemas/HTTPValidationError"
+                                }
+                            }
+                        },
+                    },
+                },
+                "summary":
+                "Get Not Decorated Get",
+                "operationId":
+                "get_not_decorated_items-not-decorated__item_id__get",
+                "parameters": [{
+                    "required": True,
+                    "schema": {
+                        "title": "Item_Id",
+                        "type": "string"
+                    },
+                    "name": "item_id",
+                    "in": "path",
+                }],
+            }
+        },
+    },
+    "components": {
+        "schemas": {
+            "Item": {
+                "title": "Item",
+                "required": ["name"],
+                "type": "object",
+                "properties": {
+                    "name": {
+                        "title": "Name",
+                        "type": "string"
+                    },
+                    "price": {
+                        "title": "Price",
+                        "type": "number"
+                    },
+                },
+            },
+            "Response400": {
+                "title": "Response400",
+                "description": "HTTP 4xx Response Schema",
+                "required": ["title", "detail", "error_code"],
+                "type": "object",
+                "properties": {
+                    "title": {
+                        "title": "Title",
+                        "type": "string"
+                    },
+                    "detail": {
+                        "title": "Detail",
+                        "type": "string"
+                    },
+                    "error_code": {
+                        "title": "Error_Code",
+                        "type": "integer"
+                    },
+                },
+            },
+            "ValidationError": {
+                "title": "ValidationError",
+                "required": ["loc", "msg", "type"],
+                "type": "object",
+                "properties": {
+                    "loc": {
+                        "title": "Location",
+                        "type": "array",
+                        "items": {
+                            "type": "string"
+                        },
+                    },
+                    "msg": {
+                        "title": "Message",
+                        "type": "string"
+                    },
+                    "type": {
+                        "title": "Error Type",
+                        "type": "string"
+                    },
+                },
+            },
+            "HTTPValidationError": {
+                "title": "HTTPValidationError",
+                "type": "object",
+                "properties": {
+                    "detail": {
+                        "title": "Detail",
+                        "type": "array",
+                        "items": {
+                            "$ref": "#/components/schemas/ValidationError"
+                        },
+                    }
+                },
+            },
+        }
+    },
+}
+
+
+def test_openapi_schema():
+    response = client.get("/openapi.json")
+    assert response.status_code == 200
+    assert response.json() == openapi_schema
+
+
+def test_get_api_route():
+    response = client.get("/items/foo")
+    assert response.status_code == 200
+    assert response.json() == {"item_id": "foo"}
+
+
+def test_get_api_route_not_decorated():
+    response = client.get("/items-not-decorated/foo")
+    assert response.status_code == 200
+    assert response.json() == {"item_id": "foo"}
+
+
+def test_delete():
+    response = client.delete("/items/foo", json={"name": "Foo"})
+    assert response.status_code == 200
+    assert response.json() == {
+        "item_id": "foo",
+        "item": {
+            "name": "Foo",
+            "price": None
+        }
+    }
+
+
+def test_head():
+    response = client.head("/items/foo")
+    assert response.status_code == 200
+    assert response.headers["x-fastapi-item-id"] == "foo"
+
+
+def test_options():
+    response = client.options("/items/foo")
+    assert response.status_code == 200
+    assert response.headers["x-fastapi-item-id"] == "foo"
+
+
+def test_patch():
+    response = client.patch("/items/foo", json={"name": "Foo"})
+    assert response.status_code == 200
+    assert response.json() == {
+        "item_id": "foo",
+        "item": {
+            "name": "Foo",
+            "price": None
+        }
+    }
+
+
+def test_trace():
+    response = client.request("trace", "/items/foo")
+    assert response.status_code == 200
+    assert response.headers["content-type"] == "message/http"