diff --git a/core/variant/container_type_validate.h b/core/variant/container_type_validate.h
index 8971fadf732..adfeaed19c0 100644
--- a/core/variant/container_type_validate.h
+++ b/core/variant/container_type_validate.h
@@ -124,9 +124,9 @@ struct ContainerTypeValidate {
 			return true; // All good, no class type requested.
 		}
 
-		StringName obj_class = object->get_class_name();
+		const StringName &obj_class = object->get_class_name();
 		if (obj_class != class_name) {
-			ERR_FAIL_COND_V_MSG(!ClassDB::is_parent_class(object->get_class_name(), class_name), false, vformat("Attempted to %s an object of type '%s' into a %s, which does not inherit from '%s'.", String(p_operation), object->get_class(), where, String(class_name)));
+			ERR_FAIL_COND_V_MSG(!ClassDB::is_parent_class(obj_class, class_name), false, vformat("Attempted to %s an object of type '%s' into a %s, which does not inherit from '%s'.", String(p_operation), object->get_class(), where, String(class_name)));
 		}
 
 		if (script.is_null()) {