diff --git a/docs/openapi.json b/docs/openapi.json
index 3c5a91f0..3a21dbf9 100644
--- a/docs/openapi.json
+++ b/docs/openapi.json
@@ -1,11 +1,9 @@
 {
-  "definitions": {},
   "info": {
     "description": "Submit workflows to be run on REANA Cloud",
     "title": "REANA Server",
     "version": "0.9.1a3"
   },
-  "parameters": {},
   "paths": {
     "/account/settings/linkedaccounts/": {},
     "/account/settings/linkedaccounts/static/{filename}": {},
@@ -4450,6 +4448,5 @@
     "/signin": {},
     "/signup/": {}
   },
-  "swagger": "2.0",
-  "tags": []
+  "swagger": "2.0"
 }
diff --git a/reana_server/rest/info.py b/reana_server/rest/info.py
index 8a45057f..0b12dae4 100644
--- a/reana_server/rest/info.py
+++ b/reana_server/rest/info.py
@@ -53,7 +53,79 @@ def info(user, **kwargs):  # noqa
         200:
           description: >-
             Request succeeded. The response contains general info about the cluster.
-          schema: InfoSchema
+          schema:
+            properties:
+              compute_backends:
+                properties:
+                  title:
+                    type: string
+                  value:
+                    items:
+                      type: string
+                    type: array
+                type: object
+              default_kubernetes_jobs_timeout:
+                properties:
+                  title:
+                    type: string
+                  value:
+                    type: string
+                type: object
+              default_kubernetes_memory_limit:
+                properties:
+                  title:
+                    type: string
+                  value:
+                    type: string
+                type: object
+              default_workspace:
+                properties:
+                  title:
+                    type: string
+                  value:
+                    type: string
+                type: object
+              kubernetes_max_memory_limit:
+                properties:
+                  title:
+                    type: string
+                  value:
+                    type: string
+                    x-nullable: true
+                type: object
+              maximum_interactive_session_inactivity_period:
+                properties:
+                  title:
+                    type: string
+                  value:
+                    type: string
+                    x-nullable: true
+                type: object
+              maximum_kubernetes_jobs_timeout:
+                properties:
+                  title:
+                    type: string
+                  value:
+                    type: string
+                type: object
+              maximum_workspace_retention_period:
+                properties:
+                  title:
+                    type: string
+                  value:
+                    type: string
+                    x-nullable: true
+                type: object
+              workspaces_available:
+                properties:
+                  title:
+                    type: string
+                  value:
+                    items:
+                      type: string
+                    type: array
+                type: object
+            type: object
           examples:
             application/json:
               {
diff --git a/scripts/generate_openapi_spec.py b/scripts/generate_openapi_spec.py
index 5b02c8f5..0d6c49ca 100644
--- a/scripts/generate_openapi_spec.py
+++ b/scripts/generate_openapi_spec.py
@@ -2,7 +2,7 @@
 # -*- coding: utf-8 -*-
 #
 # This file is part of REANA.
-# Copyright (C) 2017, 2018, 2020, 2021, 2022 CERN.
+# Copyright (C) 2017, 2018, 2020, 2021, 2022, 2023 CERN.
 #
 # REANA is free software; you can redistribute it and/or modify it
 # under the terms of the MIT License; see LICENSE file for more details.
@@ -14,6 +14,7 @@
 
 import click
 from apispec import APISpec
+from apispec_webframeworks.flask import FlaskPlugin
 from flask import current_app
 from flask.cli import with_appcontext
 from reana_commons.utils import copy_openapi_specs
@@ -57,8 +58,9 @@ def build_openapi_spec(publish):
     spec = APISpec(
         title=package,
         version=ver,
+        openapi_version="2.0",
         info=dict(description=desc),
-        plugins=("apispec.ext.flask", "apispec.ext.marshmallow"),
+        plugins=(FlaskPlugin(),),
     )
 
     # Add marshmallow schemas to the specification here
@@ -67,7 +69,7 @@ def build_openapi_spec(publish):
     # Collect OpenAPI docstrings from Flask endpoints
     for key in current_app.view_functions:
         if key != "static" and key != "get_openapi_spec":
-            spec.add_path(view=current_app.view_functions[key])
+            spec.path(view=current_app.view_functions[key])
 
     spec_json = json.dumps(
         spec.to_dict(), indent=2, separators=(",", ": "), sort_keys=True