diff --git a/HISTORY.rst b/HISTORY.rst
index 96a27eb32..69dd42bff 100644
--- a/HISTORY.rst
+++ b/HISTORY.rst
@@ -3,6 +3,10 @@
 Release History
 ===============
 
+0.1.34
+++++++
+* `azdev linter`: support to detect commmand groups which are missing in command_group_table.
+
 0.1.33
 ++++++
 * Bump `pylint` to 2.8.2 and move `--ignore` to `pylintrc` file (#301)
diff --git a/azdev/__init__.py b/azdev/__init__.py
index ee935d8b0..708697a78 100644
--- a/azdev/__init__.py
+++ b/azdev/__init__.py
@@ -4,4 +4,4 @@
 # license information.
 # -----------------------------------------------------------------------------
 
-__VERSION__ = '0.1.33'
+__VERSION__ = '0.1.34'
diff --git a/azdev/__main__.py b/azdev/__main__.py
index 2ecb1f7b4..6b047c8cc 100644
--- a/azdev/__main__.py
+++ b/azdev/__main__.py
@@ -15,7 +15,7 @@
 class AzDevCli(CLI):
 
     def get_cli_version(self):
-        from . import __VERSION__
+        from azdev import __VERSION__
         return __VERSION__
 
 
diff --git a/azdev/operations/linter/linter.py b/azdev/operations/linter/linter.py
index 88c636766..0ae250544 100644
--- a/azdev/operations/linter/linter.py
+++ b/azdev/operations/linter/linter.py
@@ -46,7 +46,7 @@ def __init__(self, command_loader=None, help_file_entries=None, loaded_help=None
         self._parameters = {}
         self._help_file_entries = set(help_file_entries.keys())
         self._command_parser = command_loader.cli_ctx.invocation.parser
-
+        self._command_groups = []
         for command_name, command in self._command_loader.command_table.items():
             self._parameters[command_name] = set()
             for name in command.arguments:
@@ -58,7 +58,18 @@ def commands(self):
 
     @property
     def command_groups(self):
-        return self._command_loader.command_group_table.keys()
+        if not self._command_groups:
+            added_command_groups = set()
+            for command_group in self._command_loader.command_group_table.keys():
+                prefix_name = ""
+                for word in command_group.split():
+                    prefix_name = "{} {}".format(prefix_name, word).strip()
+                    if prefix_name in added_command_groups:
+                        # if the parent command group is added continue
+                        continue
+                    added_command_groups.add(prefix_name)
+                    self._command_groups.append(prefix_name)
+        return self._command_groups
 
     @property
     def help_file_entries(self):
@@ -139,6 +150,9 @@ def command_group_expired(self, command_group_name):
             deprecate_info = group_kwargs.get('deprecate_info', None)
             if deprecate_info:
                 return deprecate_info.expired()
+        except KeyError:
+            # ignore command_group_name which is not in command_group_table.
+            pass
         except AttributeError:
             # Items with only token presence in the command table will not have any data. They can't be expired.
             pass