diff --git a/CHANGELOG.md b/CHANGELOG.md
index c113bef0..3ed61988 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,7 +6,8 @@ All notable changes to this project will be documented in this file.
 
 ### Fixed
 
-- NextcloudApp: `get_computation_device` function now correctly returns result in upper_case.
+- Corrected behaviour of `ocs` function for `Group Folders` app routes(they are not fully OCS API). #279
+- NextcloudApp: `get_computation_device` function now correctly returns result in upper_case. #278
 
 ## [0.15.0 - 2024-07-19]
 
diff --git a/nc_py_api/_session.py b/nc_py_api/_session.py
index bf3353c7..27bd93e6 100644
--- a/nc_py_api/_session.py
+++ b/nc_py_api/_session.py
@@ -150,7 +150,7 @@ def __init__(self, **kwargs):
         self.init_adapter()
         self.init_adapter_dav()
         self.response_headers = Headers()
-        self._ocs_regexp = re.compile(r"/ocs/v[12]\.php/")
+        self._ocs_regexp = re.compile(r"/ocs/v[12]\.php/|/apps/groupfolders/")
 
     def init_adapter(self, restart=False) -> None:
         if getattr(self, "adapter", None) is None or restart:
@@ -289,6 +289,7 @@ def _request_event_ocs(self, request: Request) -> None:
         str_url = str(request.url)
         if re.search(self._ocs_regexp, str_url) is not None:  # this is OCS call
             request.url = request.url.copy_merge_params({"format": "json"})
+            request.headers["Accept"] = "application/json"
 
     def _response_event(self, response: Response) -> None:
         str_url = str(response.request.url)
@@ -412,6 +413,7 @@ async def _request_event_ocs(self, request: Request) -> None:
         str_url = str(request.url)
         if re.search(self._ocs_regexp, str_url) is not None:  # this is OCS call
             request.url = request.url.copy_merge_params({"format": "json"})
+            request.headers["Accept"] = "application/json"
 
     async def _response_event(self, response: Response) -> None:
         str_url = str(response.request.url)