diff --git a/upgrade_tests/storage_engine_upgrade_test.py b/upgrade_tests/storage_engine_upgrade_test.py
index d791f2a751..5992e7e7b7 100644
--- a/upgrade_tests/storage_engine_upgrade_test.py
+++ b/upgrade_tests/storage_engine_upgrade_test.py
@@ -70,7 +70,7 @@ def _do_upgrade(self, login_keyspace=True):
         self.install_legacy_parsing(node1)
         node1.start(wait_for_binary_proto=True)
         if node1.get_cassandra_version() >= '5.1':
-            node1.nodetool("initializecms")
+            node1.nodetool("cms initialize")
         if self.fixture_dtest_setup.bootstrap:
             cluster.set_install_dir(install_dir=self.fixture_dtest_setup.default_install_dir)
             self.install_nodetool_legacy_parsing()
diff --git a/upgrade_tests/upgrade_through_versions_test.py b/upgrade_tests/upgrade_through_versions_test.py
index cbd8c7206b..b27a0a42ad 100644
--- a/upgrade_tests/upgrade_through_versions_test.py
+++ b/upgrade_tests/upgrade_through_versions_test.py
@@ -500,7 +500,7 @@ def upgrade_scenario(self, populate=True, create_schema=True, rolling=False, aft
                 self._check_select_count()
 
         if self.cluster.version() >= '5.1':
-            self.cluster.nodelist()[0].nodetool("initializecms")
+            self.cluster.nodelist()[0].nodetool("cms initialize")
         # run custom post-upgrade callables
         for call in after_upgrade_call:
             call()