diff --git a/openapi_core/contrib/flask/decorators.py b/openapi_core/contrib/flask/decorators.py
index 91066d85..81778ca2 100644
--- a/openapi_core/contrib/flask/decorators.py
+++ b/openapi_core/contrib/flask/decorators.py
@@ -6,6 +6,7 @@
 from typing import Type
 
 from flask.globals import request
+from flask.helpers import make_response
 from flask.wrappers import Request
 from flask.wrappers import Response
 
@@ -74,7 +75,8 @@ def _handle_request_view(
     ) -> Response:
         request = self._get_request()
         request.openapi = request_result  # type: ignore
-        return view(*args, **kwargs)
+        rv = view(*args, **kwargs)
+        return make_response(rv)
 
     def _handle_request_errors(
         self, request_result: RequestValidationResult
diff --git a/tests/integration/contrib/flask/data/v3.0/flask_factory.yaml b/tests/integration/contrib/flask/data/v3.0/flask_factory.yaml
index 3b674c7c..5d219ed3 100644
--- a/tests/integration/contrib/flask/data/v3.0/flask_factory.yaml
+++ b/tests/integration/contrib/flask/data/v3.0/flask_factory.yaml
@@ -15,10 +15,16 @@ paths:
           type: integer
     get:
       responses:
+        404:
+          description: Return error.
+          content:
+            text/html:
+              schema:
+                type: string
         200:
           description: Return the resource.
           content:
-            application/json:    
+            application/json:
               schema:
                 type: object
                 required:
diff --git a/tests/integration/contrib/flask/test_flask_decorator.py b/tests/integration/contrib/flask/test_flask_decorator.py
index be6fb118..f9f3c80a 100644
--- a/tests/integration/contrib/flask/test_flask_decorator.py
+++ b/tests/integration/contrib/flask/test_flask_decorator.py
@@ -174,7 +174,7 @@ def test_endpoint_error(self, client):
         }
         assert result.json == expected_data
 
-    def test_valid(self, client):
+    def test_valid_response_object(self, client):
         def view_response_callable(*args, **kwargs):
             from flask.globals import request
 
@@ -197,3 +197,47 @@ def view_response_callable(*args, **kwargs):
         assert result.json == {
             "data": "data",
         }
+
+    def test_valid_tuple_str(self, client):
+        def view_response_callable(*args, **kwargs):
+            from flask.globals import request
+
+            assert request.openapi
+            assert not request.openapi.errors
+            assert request.openapi.parameters == Parameters(
+                path={
+                    "id": 12,
+                }
+            )
+            return ("Not found", 404)
+
+        self.view_response_callable = view_response_callable
+
+        result = client.get("/browse/12/")
+
+        assert result.status_code == 404
+        assert result.text == "Not found"
+
+    def test_valid_tuple_dict(self, client):
+        def view_response_callable(*args, **kwargs):
+            from flask.globals import request
+
+            assert request.openapi
+            assert not request.openapi.errors
+            assert request.openapi.parameters == Parameters(
+                path={
+                    "id": 12,
+                }
+            )
+            body = dict(data="data")
+            headers = {"X-Rate-Limit": "12"}
+            return (body, headers)
+
+        self.view_response_callable = view_response_callable
+
+        result = client.get("/browse/12/")
+
+        assert result.status_code == 200
+        assert result.json == {
+            "data": "data",
+        }