diff --git a/package-lock.json b/package-lock.json
index 288ffa3..1a3b659 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -11,7 +11,7 @@
       "dependencies": {
         "@types/express": "^4.17.13",
         "express": "^4.18.1",
-        "zod": "^3.17.10"
+        "zod": "^4.0.0"
       },
       "devDependencies": {
         "@total-typescript/exercise-cli": "^0.11.0",
@@ -2804,9 +2804,9 @@
       "dev": true
     },
     "node_modules/zod": {
-      "version": "3.23.8",
-      "resolved": "https://registry.npmjs.org/zod/-/zod-3.23.8.tgz",
-      "integrity": "sha512-XBx9AXhXktjUqnepgTiE5flcKIYWi/rme0Eaj+5Y0lftuGBq+jyRu/md4WnuxqgP1ubdpNCsYEYPxrzVHD8d6g==",
+      "version": "4.0.0",
+      "resolved": "https://registry.npmjs.org/zod/-/zod-4.0.0.tgz",
+      "integrity": "sha512-9diLdTPc/L7w/5jI4C3gHYNiGHDV9IZYxo1e5LSD8cabi65WVTWWb+g2BGPEpUUCOxR4D+6O5B0AzyMdUAXwrw==",
       "funding": {
         "url": "https://github.com/sponsors/colinhacks"
       }
@@ -4663,9 +4663,9 @@
       "dev": true
     },
     "zod": {
-      "version": "3.23.8",
-      "resolved": "https://registry.npmjs.org/zod/-/zod-3.23.8.tgz",
-      "integrity": "sha512-XBx9AXhXktjUqnepgTiE5flcKIYWi/rme0Eaj+5Y0lftuGBq+jyRu/md4WnuxqgP1ubdpNCsYEYPxrzVHD8d6g=="
+      "version": "4.0.0",
+      "resolved": "https://registry.npmjs.org/zod/-/zod-4.0.0.tgz",
+      "integrity": "sha512-9diLdTPc/L7w/5jI4C3gHYNiGHDV9IZYxo1e5LSD8cabi65WVTWWb+g2BGPEpUUCOxR4D+6O5B0AzyMdUAXwrw=="
     }
   }
 }
diff --git a/package.json b/package.json
index 1263eee..33fd28f 100644
--- a/package.json
+++ b/package.json
@@ -61,6 +61,6 @@
   "dependencies": {
     "@types/express": "^4.17.13",
     "express": "^4.18.1",
-    "zod": "^3.17.10"
+    "zod": "^4.0.0"
   }
 }