diff --git a/test-app/package.json b/test-app/package.json
index 8d9defba9..49400acf5 100644
--- a/test-app/package.json
+++ b/test-app/package.json
@@ -33,7 +33,7 @@
     "@babel/plugin-proposal-decorators": "^7.21.0",
     "@ember/jquery": "^2.0.0",
     "@ember/optional-features": "^2.0.0",
-    "@ember/string": "^3.0.1",
+    "@ember/string": "^4.0.0",
     "@ember/test-helpers": "workspace:*",
     "@embroider/test-setup": "^4.0.0",
     "@glimmer/component": "^1.1.2",