diff --git a/src/file/xml-components/simple-elements.spec.ts b/src/file/xml-components/simple-elements.spec.ts
index 1a459ee815..049389a353 100644
--- a/src/file/xml-components/simple-elements.spec.ts
+++ b/src/file/xml-components/simple-elements.spec.ts
@@ -18,7 +18,7 @@ describe("BuilderElement", () => {
         });
 
         it("should create a simple BuilderElement with attributes", () => {
-            const element = new BuilderElement<{ testAttr: string }>({
+            const element = new BuilderElement<{ readonly testAttr: string }>({
                 name: "test",
                 attributes: {
                     testAttr: {