diff --git a/src/pybind/mgr/cephadm/tests/test_cephadm.py b/src/pybind/mgr/cephadm/tests/test_cephadm.py
index afe2c2e3447..e0669ecf10e 100644
--- a/src/pybind/mgr/cephadm/tests/test_cephadm.py
+++ b/src/pybind/mgr/cephadm/tests/test_cephadm.py
@@ -15,7 +15,7 @@ except ImportError:
     pass
 
 from ceph.deployment.service_spec import ServiceSpec, PlacementSpec, RGWSpec, \
-    NFSServiceSpec, IscsiServiceSpec, HostPlacementSpec, CustomContainerSpec
+    NFSServiceSpec, IscsiServiceSpec, HostPlacementSpec, CustomContainerSpec, MDSSpec
 from ceph.deployment.drive_selection.selector import DriveSelection
 from ceph.deployment.inventory import Devices, Device
 from ceph.utils import datetime_to_str, datetime_now
@@ -165,8 +165,8 @@ class TestCephadm(object):
         with with_host(cephadm_module, 'test'):
             c = cephadm_module.list_daemons(refresh=True)
             assert wait(cephadm_module, c) == []
-            with with_service(cephadm_module, ServiceSpec('mds', 'name', unmanaged=True)) as _, \
-                    with_daemon(cephadm_module, ServiceSpec('mds', 'name'), 'test') as _:
+            with with_service(cephadm_module, MDSSpec('mds', 'name', unmanaged=True)) as _, \
+                    with_daemon(cephadm_module, MDSSpec('mds', 'name'), 'test') as _:
 
                 c = cephadm_module.list_daemons()
 
@@ -227,7 +227,7 @@ class TestCephadm(object):
             with with_host(cephadm_module, 'host2'):
                 with with_service(cephadm_module, ServiceSpec('mgr', placement=PlacementSpec(count=2)),
                                   CephadmOrchestrator.apply_mgr, '', status_running=True):
-                    with with_service(cephadm_module, ServiceSpec('mds', 'test-id', placement=PlacementSpec(count=2)),
+                    with with_service(cephadm_module, MDSSpec('mds', 'test-id', placement=PlacementSpec(count=2)),
                                       CephadmOrchestrator.apply_mds, '', status_running=True):
 
                         # with no service-type. Should provide info fot both services
@@ -1291,7 +1291,7 @@ class TestCephadm(object):
 
     @mock.patch("cephadm.serve.CephadmServe._run_cephadm", _run_cephadm('{}'))
     def test_mds_config_purge(self, cephadm_module: CephadmOrchestrator):
-        spec = ServiceSpec('mds', service_id='fsname')
+        spec = MDSSpec('mds', service_id='fsname', config={'test': 'foo'})
         with with_host(cephadm_module, 'test'):
             with with_service(cephadm_module, spec, host='test'):
                 ret, out, err = cephadm_module.check_mon_command({
@@ -1310,10 +1310,11 @@ class TestCephadm(object):
     @mock.patch("cephadm.serve.CephadmServe._run_cephadm", _run_cephadm('{}'))
     @mock.patch("cephadm.services.cephadmservice.CephadmService.ok_to_stop")
     def test_daemon_ok_to_stop(self, ok_to_stop, cephadm_module: CephadmOrchestrator):
-        spec = ServiceSpec(
+        spec = MDSSpec(
             'mds',
             service_id='fsname',
-            placement=PlacementSpec(hosts=['host1', 'host2'])
+            placement=PlacementSpec(hosts=['host1', 'host2']),
+            config={'test': 'foo'}
         )
         with with_host(cephadm_module, 'host1'), with_host(cephadm_module, 'host2'):
             c = cephadm_module.apply_mds(spec)
diff --git a/src/python-common/ceph/deployment/service_spec.py b/src/python-common/ceph/deployment/service_spec.py
index eed17357907..06b0d750c76 100644
--- a/src/python-common/ceph/deployment/service_spec.py
+++ b/src/python-common/ceph/deployment/service_spec.py
@@ -1321,6 +1321,7 @@ class MDSSpec(ServiceSpec):
                  service_type: str = 'mds',
                  service_id: Optional[str] = None,
                  placement: Optional[PlacementSpec] = None,
+                 config: Optional[Dict[str, str]] = None,
                  unmanaged: bool = False,
                  preview_only: bool = False,
                  extra_container_args: Optional[List[str]] = None,
@@ -1328,6 +1329,7 @@ class MDSSpec(ServiceSpec):
         assert service_type == 'mds'
         super(MDSSpec, self).__init__('mds', service_id=service_id,
                                       placement=placement,
+                                      config=config,
                                       unmanaged=unmanaged,
                                       preview_only=preview_only,
                                       extra_container_args=extra_container_args)