diff --git a/tests/rptest/tests/polaris_catalog_smoke_test.py b/tests/rptest/tests/polaris_catalog_smoke_test.py
index bbcf8c59147b..1b27ead8a5b3 100644
--- a/tests/rptest/tests/polaris_catalog_smoke_test.py
+++ b/tests/rptest/tests/polaris_catalog_smoke_test.py
@@ -77,6 +77,8 @@ def _start_redpanda(self, catalog_prefix, client_id, client_secret,
             "rest",
             "iceberg_rest_catalog_endpoint":
             self.polaris.catalog_url,
+            "iceberg_rest_catalog_authentication_mode":
+            "oauth2",
             "iceberg_rest_catalog_client_id":
             client_id,
             "iceberg_rest_catalog_client_secret":