diff --git a/checkvsphere/cli.py b/checkvsphere/cli.py
index 16e1bed..19b372a 100644
--- a/checkvsphere/cli.py
+++ b/checkvsphere/cli.py
@@ -69,6 +69,7 @@ def run():
         for cmd in sorted(cmds):
             print(f"  {cmd}")
         print()
+        sys.exit(3)
 
 
 def main():
@@ -106,11 +107,11 @@ def main():
             traceback.print_exc(file=sys.stdout)
         sys.exit(3)
     except ConnectionRefusedError:
-        print("UNKNOWN - Connection refused")
+        print("CRITICAL - Connection refused")
         raise SystemExit(2)
     except vim.fault.VimFault as e:
         if hasattr(e, 'msg'):
-            print(f"ERROR - {e.msg}")
+            print(f"UNKNOWN - {e.msg}")
         else:
             # in case there is no msg attribute
             # According to the docs there is
@@ -118,7 +119,7 @@ def main():
             # but there is a msg attribute (which is not in the docs)
             # i don't know if it is set always
             # so fall back to the normal string representation
-            print(f"ERROR - {e}")
+            print(f"UNKNOWN - {e}")
         if int(os.environ.get("VSPHERE_DEBUG", "0")) > 0:
             traceback.print_exc(file=sys.stdout)
         raise SystemExit(3)
diff --git a/checkvsphere/tools/cli.py b/checkvsphere/tools/cli.py
index 2e3e1f9..99c82d7 100644
--- a/checkvsphere/tools/cli.py
+++ b/checkvsphere/tools/cli.py
@@ -36,6 +36,13 @@ def __call__(self, parser, namespace, values, option_string=None):
         setattr(namespace, self.dest, values)
 
 
+class MonitoringArgumentParser(argparse.ArgumentParser):
+    def exit(self, status=0, message=None):
+        if status in (0, 2):
+            status = 3
+        super().exit(status, message)
+
+
 class Parser:
     """
     Samples specific argument parser.
@@ -56,7 +63,7 @@ def __init__(self):
         One for the standard arguments and one for sample specific arguments.
         The standard group cannot be extended.
         """
-        self._parser = argparse.ArgumentParser(description='Arguments for talking to vCenter')
+        self._parser = MonitoringArgumentParser(description='Arguments for talking to vCenter')
         self._standard_args_group = self._parser.add_argument_group('standard arguments')
         self._specific_args_group = self._parser.add_argument_group('sample-specific arguments')
 
@@ -99,7 +106,7 @@ def __init__(self):
         self._standard_args_group.add_argument('--sessionfile',
                                                required=False,
                                                action='store',
-                                               help='Path to a file where the sessioncookie'
+                                               help='Path to a file where the session cookie '
                                                     'will be stored for later reuse. (EXPERIMENTAL)')
 
         self._standard_args_group.add_argument('--match-method',
diff --git a/checkvsphere/vcmd/about.py b/checkvsphere/vcmd/about.py
index 366fab3..1f0b381 100644
--- a/checkvsphere/vcmd/about.py
+++ b/checkvsphere/vcmd/about.py
@@ -25,59 +25,57 @@
 import logging
 import os
 from monplugin import Status
-from pyVmomi import vim
 from ..tools import cli, service_instance
 
 
 def run():
-    try:
-        parser = cli.Parser()
-        parser.add_optional_arguments({
-            'name_or_flags': ['--skip-permission'],
-            'options': {
-                'action': 'store_true',
-                'default': False,
-                'help': 'skips the System.View permission check',
-            }
-        })
+    parser = cli.Parser()
+    parser.add_optional_arguments({
+        'name_or_flags': ['--skip-permission'],
+        'options': {
+            'action': 'store_true',
+            'default': False,
+            'help': 'skips the System.View permission check',
+        }
+    })
 
-        args = parser.get_args()
-        si = service_instance.connect(args)
-        about = si.content.about
-        status = Status.OK
-        clock = True
-        if not args.skip_permission:
-            try:
-                clock = si.serverClock
-            except Exception:
-                logging.debug("no server clock", exc_info=1)
-                status = Status.CRITICAL
-                clock = None
-                if args.sessionfile:
-                    try:
-                        logging.debug(f"deleting {args.sessionfile}")
-                        os.unlink(args.sessionfile)
-                    except Exception:
-                        logging.debug(f"unlink {args.sessionfile} failed", exc_info=1)
+    args = parser.get_args()
+    si = service_instance.connect(args)
+    about = si.content.about
+    status = Status.OK
+    clock = True
+    if not args.skip_permission:
+        try:
+            clock = si.serverClock
+        except Exception:
+            logging.debug("no server clock", exc_info=1)
+            status = Status.CRITICAL
+            clock = None
+            if args.sessionfile:
+                try:
+                    logging.debug(f"deleting {args.sessionfile}")
+                    os.unlink(args.sessionfile)
+                except Exception:
+                    logging.debug(f"unlink {args.sessionfile} failed", exc_info=1)
 
-        out = (
-            f'{status.name}: '
-            f'{ "No System.View permission, " if not clock  else "" }'
-            f'{ about.fullName }, '
-            f'api: { about.apiType }/{ about.apiVersion }, '
-            f'product: { about.licenseProductName } { about.licenseProductVersion }'
-        )
-        print(out)
-        raise SystemExit(status.value)
-    except vim.fault.VimFault as e:
-        if hasattr(e, 'msg'):
-            print(f"ERROR: {e.msg}")
-        else:
-            print(f"ERROR: {e}")
-        raise SystemExit(2)
-    except Exception as e:
-        print(f"ERROR: {e}")
-        raise SystemExit(2)
+    out = (
+        f'{status.name}: '
+        f'{ "No System.View permission, " if not clock  else "" }'
+        f'{ about.fullName }, '
+        f'api: { about.apiType }/{ about.apiVersion }, '
+        f'product: { about.licenseProductName } { about.licenseProductVersion }'
+    )
+    print(out)
+    raise SystemExit(status.value)
 
 if __name__ == "__main__":
-    run()
+    try:
+        run()
+    except SystemExit as e:
+        if not isinstance(e.code, int) or e.code > 3 or e.code < 0:
+            print("UNKNOWN EXIT CODE")
+            raise SystemExit(Status.UNKNOWN)
+        raise
+    except Exception as e:
+        print("UNKNOWN - " + str(e))
+        raise SystemExit(Status.UNKNOWN)