diff --git a/src/caosdb/configuration.py b/src/caosdb/configuration.py
index f9ea31993ac670aa5580bdade0cfd20067562724..51e3749aaca3045afec9334ef987a174d5d19f26 100644
--- a/src/caosdb/configuration.py
+++ b/src/caosdb/configuration.py
@@ -86,10 +86,10 @@ def config_to_yaml(config):
 def validate_yaml_schema(valobj):
     # TODO: Re-enable warning once the schema has been extended to also cover
     # SSS pycaosdb.inis and integration tests.
-    # if optional_jsonschema_validate:
-    with open(os.path.join(os.path.dirname(__file__), "schema-pycaosdb-ini.yml")) as f:
-        schema = yaml.load(f, Loader=yaml.SafeLoader)
-    optional_jsonschema_validate(instance=valobj, schema=schema["schema-pycaosdb-ini"])
+    if optional_jsonschema_validate:
+        with open(os.path.join(os.path.dirname(__file__), "schema-pycaosdb-ini.yml")) as f:
+            schema = yaml.load(f, Loader=yaml.SafeLoader)
+        optional_jsonschema_validate(instance=valobj, schema=schema["schema-pycaosdb-ini"])
     # else:
     #     warnings.warn("""
     #                     Warning: The validation could not be performed because `jsonschema` is not installed.