diff --git a/CHANGES.md b/CHANGES.md
index f7d16b55..b98397e6 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -9,6 +9,7 @@ and pick the appropriate release branch.
 
 **Features and Improvements**:
 
+- refactored [NCLM ca handler](docs/nclm.md) using the external REST-API
 - [ca handler](docs/digicert.md) using the [DigiCert CertCentral API](https://dev.digicert.com/en/certcentral-apis.html)
 - [ca handler](docs/entrust.md) using the Entrust ECS Enterprise APIl
 - [EAB Profiling support](docs/eab_profiling.md) in Microsoft CA handlers
diff --git a/acme_srv/challenge.py b/acme_srv/challenge.py
index 950c0be3..29327c13 100644
--- a/acme_srv/challenge.py
+++ b/acme_srv/challenge.py
@@ -97,6 +97,7 @@ def _challenge_validate(self, pub_key: Dict[str, str], challenge_name: str, chal
         for _ele in range(0, 5):
 
             result, invalid = self._challenge_validate_loop(challenge_name, challenge_dic, payload, jwk_thumbprint)
+            # pylint: disable=r1723
             if result or invalid:
                 # break loop if we got any good or bad response
                 break
diff --git a/acme_srv/helper.py b/acme_srv/helper.py
index 749940ee..3b735b08 100644
--- a/acme_srv/helper.py
+++ b/acme_srv/helper.py
@@ -1862,7 +1862,8 @@ def eab_profile_string_check(logger, cahandler, key, value):
 
     logger.debug('Helper.eab_profile_string_check() ended')
 
-def request_operation(logger: logging.Logger, headers: Dict[str, str] = {}, proxy: Dict[str, str] = {}, timeout: int = 20, url: str = None, session=requests, method: str = 'GET', payload: Dict[str, str] = None):
+
+def request_operation(logger: logging.Logger, headers: Dict[str, str] = None, proxy: Dict[str, str] = None, timeout: int = 20, url: str = None, session=requests, method: str = 'GET', payload: Dict[str, str] = None):
     """ check if a for a string value taken from profile if its a variable inside a class and apply value """
     logger.debug('Helper.api_operation(): method: %s', method)
 
diff --git a/docs/nclm.md b/docs/nclm.md
index 54dbffe8..bdcc49ed 100644
--- a/docs/nclm.md
+++ b/docs/nclm.md
@@ -4,7 +4,8 @@
 
 ## Pre-requisites
 
-- NCLM 19.0.0 or higher needs to be up and running
+- NCLM 24.2.0 or higher needs to be up and running
+- the external REST-API needs to be enabled
 - username and password to access NCLM via REST-Service
 - is a container created in NCLM which can be used to store the certificates