diff --git a/package-lock.json b/package-lock.json
index bda83cc..ff622b2 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -11,7 +11,7 @@
       "dependencies": {
         "@modelcontextprotocol/sdk": "^1.24.0",
         "express": "^5.1.0",
-        "zod": "^3.23.8",
+        "zod": "^4.1.13",
         "zod-to-json-schema": "^3.24.6"
       },
       "bin": {
@@ -609,6 +609,7 @@
       "resolved": "https://registry.npmjs.org/express/-/express-5.1.0.tgz",
       "integrity": "sha512-DT9ck5YIRU+8GYzzU5kT3eHGA5iL+1Zd0EutOmTE9Dtk+Tvuzd23VBU+ec7HPNSTxXYO55gPV/hq4pSBJDjFpA==",
       "license": "MIT",
+      "peer": true,
       "dependencies": {
         "accepts": "^2.0.0",
         "body-parser": "^2.2.0",
@@ -1764,10 +1765,11 @@
       "license": "ISC"
     },
     "node_modules/zod": {
-      "version": "3.25.76",
-      "resolved": "https://registry.npmjs.org/zod/-/zod-3.25.76.tgz",
-      "integrity": "sha512-gzUt/qt81nXsFGKIFcC3YnfEAx5NkunCfnDlvuBSSFS02bcXu4Lmea0AFIUwbLWxWPx3d9p8S5QoaujKcNQxcQ==",
+      "version": "4.1.13",
+      "resolved": "https://registry.npmjs.org/zod/-/zod-4.1.13.tgz",
+      "integrity": "sha512-AvvthqfqrAhNH9dnfmrfKzX5upOdjUVJYFqNSlkmGf64gRaTzlPwz99IHYnVs28qYAybvAlBV+H7pn0saFY4Ig==",
       "license": "MIT",
+      "peer": true,
       "funding": {
         "url": "https://github.com/sponsors/colinhacks"
       }
diff --git a/package.json b/package.json
index 5cf98e5..7c2f13f 100644
--- a/package.json
+++ b/package.json
@@ -45,7 +45,7 @@
   "dependencies": {
     "@modelcontextprotocol/sdk": "^1.24.0",
     "express": "^5.1.0",
-    "zod": "^3.23.8",
+    "zod": "^4.1.13",
     "zod-to-json-schema": "^3.24.6"
   },
   "devDependencies": {