diff --git a/lib/util/ast.js b/lib/util/ast.js
index 0bee8480fd..da27a9f855 100644
--- a/lib/util/ast.js
+++ b/lib/util/ast.js
@@ -66,6 +66,7 @@ function findReturnStatement(node) {
  *
  * @param {ASTNode} ASTNode The AST node being checked
  * @param {function} enterFunc Function to execute for each returnStatement found
+ * @returns {undefined}
  */
 function traverseReturns(ASTNode, enterFunc) {
   const nodeType = ASTNode.type;