diff --git a/CHANGELOG.md b/CHANGELOG.md
index 98e4026f56..ae3e166f3f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -111,6 +111,7 @@ Release report: TBD
 - Fix error in requirements.txt ([#3689](https://github.com/wazuh/wazuh-qa/pull/3689)) \- (Framework)
 - Fix sleep time in `test_agent_default_group_added`. ([#3692](https://github.com/wazuh/wazuh-qa/pull/3692)) \- (Tests)
 - Fix syscollector deltas integration tests. ([#3695](https://github.com/wazuh/wazuh-qa/pull/3695)) \- (Tests)
+- Fix test_response_postprocessing: duplicated slash in API endpoints ([#4048](https://github.com/wazuh/wazuh-qa/pull/4048)) \- (Tests)
 
 ### Removed
 
diff --git a/tests/integration/test_api/conftest.py b/tests/integration/test_api/conftest.py
index b83d7419a5..eae910d6a8 100644
--- a/tests/integration/test_api/conftest.py
+++ b/tests/integration/test_api/conftest.py
@@ -4,15 +4,16 @@
 
 import os
 import shutil
+
 import pytest
 
 import wazuh_testing as fw
 from wazuh_testing import api
-from wazuh_testing.tools.file import truncate_file
-from wazuh_testing.tools.monitoring import FileMonitor
-from wazuh_testing.tools import services as svcs
 from wazuh_testing.modules.api import event_monitor as evm
 from wazuh_testing.tools import configuration as conf
+from wazuh_testing.tools import services as svcs
+from wazuh_testing.tools.file import truncate_file
+from wazuh_testing.tools.monitoring import FileMonitor
 
 
 @pytest.fixture(scope='module')
@@ -144,6 +145,7 @@ def restart_api_module(request):
 
     # Start Wazuh API
     svcs.control_service('start')
+    evm.check_api_start_log(file_monitor)
 
 
 @pytest.fixture(scope='module')
diff --git a/tests/integration/test_api/test_middlewares/test_response_postprocessing.py b/tests/integration/test_api/test_middlewares/test_response_postprocessing.py
index fd92f858ce..166c7340a7 100644
--- a/tests/integration/test_api/test_middlewares/test_response_postprocessing.py
+++ b/tests/integration/test_api/test_middlewares/test_response_postprocessing.py
@@ -122,7 +122,7 @@ def test_response_postprocessing(restart_api_module, get_api_details, method, en
     headers = api_details['auth_headers'] if use_login_token else api.get_login_headers('wrong_user', 'wrong_password')
 
     # Make an API request
-    response = getattr(requests, method.lower())(f"{api_details['base_url']}/{endpoint_url}", headers=headers,
+    response = getattr(requests, method.lower())(f"{api_details['base_url']}{endpoint_url}", headers=headers,
                                                  verify=False, json=json_body)
 
     assert response.headers['Content-Type'] == 'application/problem+json; charset=utf-8'