diff --git a/backend/package.json b/backend/package.json
index a0bc19c1..ca394e88 100644
--- a/backend/package.json
+++ b/backend/package.json
@@ -61,7 +61,7 @@
     "zod": "^4.3.6"
   },
   "devDependencies": {
-    "@stryker-mutator/core": "^8.7.1",
+    "@stryker-mutator/core": "^9.6.1",
     "@stryker-mutator/vitest-runner": "^8.7.1",
     "@types/bcryptjs": "^2.4.6",
     "@types/cors": "^2.8.17",