--- /dev/null
+<?php
+/**
+ * @file
+ * @license https://opensource.org/licenses/Apache-2.0 Apache-2.0
+ */
+
+namespace Wikimedia\CSS\Objects;
+
+/**
+ * Exists because DeclarationOrAtRuleList needs to be able to contain both Declarations
+ * and AtRules.
+ */
+interface DeclarationOrAtRule extends CSSObject {
+}