diff --git a/src/mpyl/steps/deploy/bpm/cluster.py b/src/mpyl/steps/deploy/bpm/cluster.py
index 585f2d6be..425fb1f01 100644
--- a/src/mpyl/steps/deploy/bpm/cluster.py
+++ b/src/mpyl/steps/deploy/bpm/cluster.py
@@ -25,7 +25,7 @@ def deploy_diagram_to_cluster(logger: Logger, config: CamundaConfig):
         environment_variables = {
             "ZEEBE_ADDRESS": config.zeebe_credentials.cluster_id,
             "ZEEBE_CLIENT_ID": config.zeebe_credentials.client_id,
-            "ZEEBE_CLIENT_SECRET": config.zeebe_credentials.client
+            "ZEEBE_CLIENT_SECRET": config.zeebe_credentials.client_secret,
         }
 
-        custom_check_output(logger, command, environment_variables)
+        custom_check_output(logger, command, environment_variables=environment_variables)
diff --git a/src/mpyl/utilities/subprocess/__init__.py b/src/mpyl/utilities/subprocess/__init__.py
index 47d38bdff..dd5498270 100644
--- a/src/mpyl/utilities/subprocess/__init__.py
+++ b/src/mpyl/utilities/subprocess/__init__.py
@@ -15,7 +15,7 @@ def custom_check_output(
     command: Union[str, list[str]],
     capture_stdout: bool = False,
     use_print: bool = False,
-    environment_variables: dict[str, str] = None,
+    environment_variables: dict[str, str] = dict[None, None],
 ) -> Output:
     """
     Wrapper around subprocess.Popen
@@ -38,7 +38,11 @@ def custom_check_output(
             return Output(success=True, message=out)
 
         with subprocess.Popen(
-            command, stdout=subprocess.PIPE, stderr=subprocess.STDOUT, text=True, env=environment_variables
+            command,
+            stdout=subprocess.PIPE,
+            stderr=subprocess.STDOUT,
+            text=True,
+            env=environment_variables,
         ) as process:
             if not process.stdout:
                 raise RuntimeError(