diff --git a/manilaclient/osc/v2/share.py b/manilaclient/osc/v2/share.py
index 682734964..1309dccb9 100644
--- a/manilaclient/osc/v2/share.py
+++ b/manilaclient/osc/v2/share.py
@@ -796,6 +796,7 @@ class SetShare(command.Command):
             metavar="<task-state>",
             required=False,
             default=None,
+            nargs='?',
             help=_("Indicate which task state to assign the share. Options "
                    "include migration_starting, migration_in_progress, "
                    "migration_completing, migration_success, migration_error, "
@@ -844,9 +845,12 @@ class SetShare(command.Command):
                 LOG.error(_(
                     "Failed to set status for the share: %s"), e)
                 result += 1
-        if parsed_args.task_state:
+        if hasattr(parsed_args, 'task_state'):
+            task_state = parsed_args.task_state
+            if task_state and task_state.lower() == "none":
+                task_state = None
             try:
-                share_obj.reset_task_state(parsed_args.task_state)
+                share_obj.reset_task_state(task_state)
             except Exception as e:
                 LOG.error(_("Failed to update share task state "
                           "%s"), e)
diff --git a/manilaclient/osc/v2/share_servers.py b/manilaclient/osc/v2/share_servers.py
index dda2d9761..31de153ad 100644
--- a/manilaclient/osc/v2/share_servers.py
+++ b/manilaclient/osc/v2/share_servers.py
@@ -435,6 +435,7 @@ class SetShareServer(command.Command):
             metavar="<task-state>",
             required=False,
             default=None,
+            nargs='?',
             help=_("Indicate which task state to assign the share server. "
                    "Options include migration_starting, migration_in_progress,"
                    " migration_completing, migration_success, migration_error,"
@@ -471,16 +472,19 @@ class SetShareServer(command.Command):
                 LOG.error(msg)
                 raise exceptions.CommandError(msg)
 
-        if parsed_args.task_state:
+        if hasattr(parsed_args, 'task_state'):
             if share_client.api_version < api_versions.APIVersion("2.57"):
                 raise exceptions.CommandError(
                     "Setting the state of a share server is only available "
                     "with manila API version >= 2.57")
             else:
+                task_state = parsed_args.task_state
+                if task_state and task_state.lower() == "none":
+                    task_state = None
                 result = 0
                 try:
                     share_client.share_servers.reset_task_state(
-                        share_server, parsed_args.task_state)
+                        share_server, task_state)
                 except Exception as e:
                     LOG.error(_("Failed to update share server task state "
                                 "%s"), e)
diff --git a/manilaclient/tests/unit/osc/v2/test_share.py b/manilaclient/tests/unit/osc/v2/test_share.py
index fe6a5de0c..ff9cf52cf 100644
--- a/manilaclient/tests/unit/osc/v2/test_share.py
+++ b/manilaclient/tests/unit/osc/v2/test_share.py
@@ -1406,6 +1406,34 @@ class TestShareSet(TestShare):
         self._share.reset_task_state.assert_called_with(new_task_state)
         self.assertIsNone(result)
 
+    def test_share_set_task_state_none(self):
+        arglist = [
+            self._share.id,
+            '--task-state'
+        ]
+        verifylist = [
+            ('share', self._share.id),
+            ('task_state', None)
+        ]
+        parsed_args = self.check_parser(self.cmd, arglist, verifylist)
+        result = self.cmd.take_action(parsed_args)
+        self._share.reset_task_state.assert_called_with(None)
+        self.assertIsNone(result)
+
+    def test_share_set_task_state_string_none(self):
+        arglist = [
+            self._share.id,
+            '--task-state', 'None'
+        ]
+        verifylist = [
+            ('share', self._share.id),
+            ('task_state', 'None')
+        ]
+        parsed_args = self.check_parser(self.cmd, arglist, verifylist)
+        result = self.cmd.take_action(parsed_args)
+        self._share.reset_task_state.assert_called_with(None)
+        self.assertIsNone(result)
+
 
 class TestShareUnset(TestShare):
 
diff --git a/manilaclient/tests/unit/osc/v2/test_share_servers.py b/manilaclient/tests/unit/osc/v2/test_share_servers.py
index dcb2f12a4..f029cce2c 100644
--- a/manilaclient/tests/unit/osc/v2/test_share_servers.py
+++ b/manilaclient/tests/unit/osc/v2/test_share_servers.py
@@ -564,6 +564,44 @@ class TestSetShareServer(TestShareServer):
             parsed_args.task_state)
         self.assertIsNone(result)
 
+    def test_share_server_set_task_state_none(self):
+        arglist = [
+            self.share_server.id,
+            '--task-state',
+        ]
+        verifylist = [
+            ('share_server', self.share_server.id),
+            ('task_state', None)
+        ]
+
+        parsed_args = self.check_parser(self.cmd, arglist, verifylist)
+
+        result = self.cmd.take_action(parsed_args)
+
+        self.servers_mock.reset_task_state.assert_called_with(
+            self.share_server,
+            None)
+        self.assertIsNone(result)
+
+    def test_share_server_set_task_state_string_none(self):
+        arglist = [
+            self.share_server.id,
+            '--task-state', 'None'
+        ]
+        verifylist = [
+            ('share_server', self.share_server.id),
+            ('task_state', 'None')
+        ]
+
+        parsed_args = self.check_parser(self.cmd, arglist, verifylist)
+
+        result = self.cmd.take_action(parsed_args)
+
+        self.servers_mock.reset_task_state.assert_called_with(
+            self.share_server,
+            None)
+        self.assertIsNone(result)
+
     def test_share_server_set_status_exception(self):
         arglist = [
             self.share_server.id,
diff --git a/releasenotes/notes/bug-2108991-fix-task-state-none-handling-in-osc-share-set-307f3f4a2b232dd8.yaml b/releasenotes/notes/bug-2108991-fix-task-state-none-handling-in-osc-share-set-307f3f4a2b232dd8.yaml
new file mode 100644
index 000000000..1b2d4a809
--- /dev/null
+++ b/releasenotes/notes/bug-2108991-fix-task-state-none-handling-in-osc-share-set-307f3f4a2b232dd8.yaml
@@ -0,0 +1,7 @@
+---
+fixes:
+  - |
+    The `openstack share set` and `openstack share server set` commands now
+    properly handle the `--task-state` argument when given no value or "None",
+    sending a proper null value to the API. For more details, please refer to
+    `Launchpad bug #2108991 <https://bugs.launchpad.net/python-manilaclient/+bug/2108991>`_.