diff --git a/connexion/apps/abstract.py b/connexion/apps/abstract.py
index 63bcf842a..f70767984 100644
--- a/connexion/apps/abstract.py
+++ b/connexion/apps/abstract.py
@@ -122,6 +122,7 @@ def add_api(
         specification: t.Union[pathlib.Path, str, dict],
         *,
         base_path: t.Optional[str] = None,
+        name: t.Optional[str] = None,
         arguments: t.Optional[dict] = None,
         auth_all_paths: t.Optional[bool] = None,
         jsonifier: t.Optional[Jsonifier] = None,
@@ -144,6 +145,8 @@ def add_api(
             to file.
         :param base_path: Base path to host the API. This overrides the basePath / servers in the
             specification.
+        :param name: Name to register the API with. If no name is passed, the base_path is used
+            as name instead.
         :param arguments: Arguments to substitute the specification using Jinja.
         :param auth_all_paths: whether to authenticate not paths not defined in the specification.
             Defaults to False.
@@ -175,6 +178,7 @@ def add_api(
         return self.middleware.add_api(
             specification,
             base_path=base_path,
+            name=name,
             arguments=arguments,
             auth_all_paths=auth_all_paths,
             jsonifier=jsonifier,
diff --git a/connexion/apps/asynchronous.py b/connexion/apps/asynchronous.py
index 1d0e3fc96..9974381fd 100644
--- a/connexion/apps/asynchronous.py
+++ b/connexion/apps/asynchronous.py
@@ -93,14 +93,18 @@ class AsyncMiddlewareApp(RoutedMiddleware[AsyncApi]):
     api_cls = AsyncApi
 
     def __init__(self) -> None:
-        self.apis: t.Dict[str, AsyncApi] = {}
+        self.apis: t.Dict[str, t.List[AsyncApi]] = {}
         self.operations: t.Dict[str, AsyncOperation] = {}
         self.router = Router()
         super().__init__(self.router)
 
-    def add_api(self, *args, **kwargs):
+    def add_api(self, *args, name: str = None, **kwargs):
         api = super().add_api(*args, **kwargs)
-        self.router.mount(api.base_path, api.router)
+
+        if name is not None:
+            self.router.mount(api.base_path, api.router, name=name)
+        else:
+            self.router.mount(api.base_path, api.router)
         return api
 
     def add_url_rule(
diff --git a/connexion/apps/flask.py b/connexion/apps/flask.py
index 2121348b4..1bb1e229b 100644
--- a/connexion/apps/flask.py
+++ b/connexion/apps/flask.py
@@ -155,9 +155,14 @@ def common_error_handler(self, exception: Exception) -> FlaskResponse:
             (response.body, response.status_code, response.headers)
         )
 
-    def add_api(self, specification, **kwargs):
+    def add_api(self, specification, *, name: str = None, **kwargs):
         api = FlaskApi(specification, **kwargs)
-        self.app.register_blueprint(api.blueprint)
+
+        if name is not None:
+            self.app.register_blueprint(api.blueprint, name=name)
+        else:
+            self.app.register_blueprint(api.blueprint)
+
         return api
 
     def add_url_rule(
diff --git a/connexion/middleware/abstract.py b/connexion/middleware/abstract.py
index 781d5329b..9be98fe6e 100644
--- a/connexion/middleware/abstract.py
+++ b/connexion/middleware/abstract.py
@@ -2,6 +2,7 @@
 import logging
 import pathlib
 import typing as t
+from collections import defaultdict
 
 from starlette.types import ASGIApp, Receive, Scope, Send
 
@@ -182,7 +183,7 @@ def __init__(
     ) -> None:
         super().__init__(specification, *args, **kwargs)
         self.next_app = next_app
-        self.operations: t.MutableMapping[str, OP] = {}
+        self.operations: t.MutableMapping[t.Optional[str], OP] = {}
 
     def add_paths(self) -> None:
         paths = self.specification.get("paths", {})
@@ -232,11 +233,11 @@ class RoutedMiddleware(SpecMiddleware, t.Generic[API]):
 
     def __init__(self, app: ASGIApp) -> None:
         self.app = app
-        self.apis: t.Dict[str, API] = {}
+        self.apis: t.Dict[str, t.List[API]] = defaultdict(list)
 
     def add_api(self, specification: t.Union[pathlib.Path, str, dict], **kwargs) -> API:
         api = self.api_cls(specification, next_app=self.app, **kwargs)
-        self.apis[api.base_path] = api
+        self.apis[api.base_path].append(api)
         return api
 
     async def __call__(self, scope: Scope, receive: Receive, send: Send) -> None:
@@ -254,19 +255,19 @@ async def __call__(self, scope: Scope, receive: Receive, send: Send) -> None:
             )
         api_base_path = connexion_context.get("api_base_path")
         if api_base_path is not None and api_base_path in self.apis:
-            api = self.apis[api_base_path]
-            operation_id = connexion_context.get("operation_id")
-            try:
-                operation = api.operations[operation_id]
-            except KeyError as e:
-                if operation_id is None:
-                    logger.debug("Skipping operation without id.")
-                    await self.app(scope, receive, send)
-                    return
+            for api in self.apis[api_base_path]:
+                operation_id = connexion_context.get("operation_id")
+                try:
+                    operation = api.operations[operation_id]
+                except KeyError:
+                    if operation_id is None:
+                        logger.debug("Skipping operation without id.")
+                        await self.app(scope, receive, send)
+                        return
                 else:
-                    raise MissingOperation("Encountered unknown operation_id.") from e
-            else:
-                return await operation(scope, receive, send)
+                    return await operation(scope, receive, send)
+
+            raise MissingOperation("Encountered unknown operation_id.")
 
         await self.app(scope, receive, send)
 
diff --git a/connexion/middleware/main.py b/connexion/middleware/main.py
index 1d775f817..ded10d925 100644
--- a/connexion/middleware/main.py
+++ b/connexion/middleware/main.py
@@ -332,6 +332,7 @@ def add_api(
         specification: t.Union[pathlib.Path, str, dict],
         *,
         base_path: t.Optional[str] = None,
+        name: t.Optional[str] = None,
         arguments: t.Optional[dict] = None,
         auth_all_paths: t.Optional[bool] = None,
         jsonifier: t.Optional[Jsonifier] = None,
@@ -354,6 +355,8 @@ def add_api(
             to file.
         :param base_path: Base path to host the API. This overrides the basePath / servers in the
             specification.
+        :param name: Name to register the API with. If no name is passed, the base_path is used
+            as name instead.
         :param arguments: Arguments to substitute the specification using Jinja.
         :param auth_all_paths: whether to authenticate not paths not defined in the specification.
             Defaults to False.
@@ -410,7 +413,9 @@ def add_api(
             security_map=security_map,
         )
 
-        api = API(specification, base_path=base_path, **options.__dict__, **kwargs)
+        api = API(
+            specification, base_path=base_path, name=name, **options.__dict__, **kwargs
+        )
         self.apis.append(api)
 
     def add_error_handler(
diff --git a/connexion/middleware/routing.py b/connexion/middleware/routing.py
index 065fb7cf4..bb3221b31 100644
--- a/connexion/middleware/routing.py
+++ b/connexion/middleware/routing.py
@@ -128,6 +128,17 @@ def add_api(
             next_app=self.app,
             **kwargs,
         )
+
+        # If an API with the same base_path was already registered, chain the new API as its
+        # default. This way, if no matching route is found on the first API, the request is
+        # forwarded to the new API.
+        for route in self.router.routes:
+            if (
+                isinstance(route, starlette.routing.Mount)
+                and route.path == api.base_path
+            ):
+                route.app.default = api.router
+
         self.router.mount(api.base_path, app=api.router)
 
     async def __call__(self, scope: Scope, receive: Receive, send: Send) -> None:
diff --git a/connexion/middleware/security.py b/connexion/middleware/security.py
index 136dfecea..6c4d9010f 100644
--- a/connexion/middleware/security.py
+++ b/connexion/middleware/security.py
@@ -111,7 +111,7 @@ def __init__(
         if auth_all_paths:
             self.add_auth_on_not_found()
         else:
-            self.operations: t.MutableMapping[str, SecurityOperation] = {}
+            self.operations: t.MutableMapping[t.Optional[str], SecurityOperation] = {}
 
         self.add_paths()
 
diff --git a/tests/api/test_bootstrap_multiple_spec.py b/tests/api/test_bootstrap_multiple_spec.py
new file mode 100644
index 000000000..9bc299b2c
--- /dev/null
+++ b/tests/api/test_bootstrap_multiple_spec.py
@@ -0,0 +1,48 @@
+import json
+
+import pytest
+
+from conftest import TEST_FOLDER
+
+SPECS = [
+    pytest.param(
+        [
+            {"specification": "swagger_greeting.yaml", "name": "greeting"},
+            {"specification": "swagger_bye.yaml", "name": "bye"},
+        ],
+        id="swagger",
+    ),
+    pytest.param(
+        [
+            {"specification": "openapi_greeting.yaml", "name": "greeting"},
+            {"specification": "openapi_bye.yaml", "name": "bye"},
+        ],
+        id="openapi",
+    ),
+]
+
+
+@pytest.mark.parametrize("specs", SPECS)
+def test_app_with_multiple_definition(
+    multiple_yaml_same_basepath_dir, specs, app_class
+):
+    app = app_class(
+        __name__,
+        specification_dir=".."
+        / multiple_yaml_same_basepath_dir.relative_to(TEST_FOLDER),
+    )
+
+    for spec in specs:
+        print(spec)
+        app.add_api(**spec)
+
+    app_client = app.test_client()
+
+    response = app_client.post("/v1.0/greeting/Igor")
+    assert response.status_code == 200
+    print(response.text)
+    assert response.json()["greeting"] == "Hello Igor"
+
+    response = app_client.get("/v1.0/bye/Musti")
+    assert response.status_code == 200
+    assert response.text == "Goodbye Musti"
diff --git a/tests/conftest.py b/tests/conftest.py
index f5dab724b..762121b76 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -42,6 +42,11 @@ def json_validation_spec_dir():
     return FIXTURES_FOLDER / "json_validation"
 
 
+@pytest.fixture
+def multiple_yaml_same_basepath_dir():
+    return FIXTURES_FOLDER / "multiple_yaml_same_basepath"
+
+
 @pytest.fixture(scope="session")
 def json_datetime_dir():
     return FIXTURES_FOLDER / "datetime_support"
diff --git a/tests/fixtures/multiple_yaml_same_basepath/openapi_bye.yaml b/tests/fixtures/multiple_yaml_same_basepath/openapi_bye.yaml
new file mode 100644
index 000000000..1970a9b15
--- /dev/null
+++ b/tests/fixtures/multiple_yaml_same_basepath/openapi_bye.yaml
@@ -0,0 +1,28 @@
+openapi: 3.0.0
+info:
+  title: '{{title}}'
+  version: '1.0'
+paths:
+  '/bye/{name}':
+    get:
+      summary: Generate goodbye
+      description: Generates a goodbye message.
+      operationId: fakeapi.hello.get_bye
+      responses:
+        '200':
+          description: goodbye response
+          content:
+            text/plain:
+              schema:
+                type: string
+        default:
+          description: unexpected error
+      parameters:
+        - name: name
+          in: path
+          description: Name of the person to say bye.
+          required: true
+          schema:
+            type: string
+servers:
+  - url: /v1.0
diff --git a/tests/fixtures/multiple_yaml_same_basepath/openapi_greeting.yaml b/tests/fixtures/multiple_yaml_same_basepath/openapi_greeting.yaml
new file mode 100644
index 000000000..eb9d57597
--- /dev/null
+++ b/tests/fixtures/multiple_yaml_same_basepath/openapi_greeting.yaml
@@ -0,0 +1,28 @@
+openapi: 3.0.0
+info:
+  title: '{{title}}'
+  version: '1.0'
+paths:
+  '/greeting/{name}':
+    post:
+      summary: Generate greeting
+      description: Generates a greeting message.
+      operationId: fakeapi.hello.post_greeting
+      responses:
+        '200':
+          description: greeting response
+          content:
+            'application/json':
+              schema:
+                type: object
+      parameters:
+        - name: name
+          in: path
+          description: Name of the person to greet.
+          required: true
+          schema:
+            type: string
+
+      
+servers:
+  - url: /v1.0
diff --git a/tests/fixtures/multiple_yaml_same_basepath/swagger_bye.yaml b/tests/fixtures/multiple_yaml_same_basepath/swagger_bye.yaml
new file mode 100644
index 000000000..2905e126c
--- /dev/null
+++ b/tests/fixtures/multiple_yaml_same_basepath/swagger_bye.yaml
@@ -0,0 +1,29 @@
+swagger: "2.0"
+
+info:
+  title: "{{title}}"
+  version: "1.0"
+
+basePath: /v1.0
+
+paths:
+  /bye/{name}:
+    get:
+      summary: Generate goodbye
+      description: Generates a goodbye message.
+      operationId: fakeapi.hello.get_bye
+      produces:
+        - text/plain
+      responses:
+        '200':
+          description: goodbye response
+          schema:
+            type: string
+        default:
+          description: "unexpected error"
+      parameters:
+        - name: name
+          in: path
+          description: Name of the person to say bye.
+          required: true
+          type: string
diff --git a/tests/fixtures/multiple_yaml_same_basepath/swagger_greeting.yaml b/tests/fixtures/multiple_yaml_same_basepath/swagger_greeting.yaml
new file mode 100644
index 000000000..f3246b530
--- /dev/null
+++ b/tests/fixtures/multiple_yaml_same_basepath/swagger_greeting.yaml
@@ -0,0 +1,25 @@
+swagger: "2.0"
+
+info:
+  title: "{{title}}"
+  version: "1.0"
+
+basePath: /v1.0
+
+paths:
+ /greeting/{name}:
+    post:
+      summary: Generate greeting
+      description: Generates a greeting message.
+      operationId: fakeapi.hello.post_greeting
+      responses:
+        200:
+          description: greeting response
+          schema:
+            type: object
+      parameters:
+        - name: name
+          in: path
+          description: Name of the person to greet.
+          required: true
+          type: string
\ No newline at end of file