diff --git a/package-lock.json b/package-lock.json
index c8fe2e6..115de11 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -14,7 +14,7 @@
         "eventsource-parser": "^3.0.6",
         "express": "^5.1.0",
         "jose": "^6.1.2",
-        "zod": "^3.25.76"
+        "zod": "^4.1.13"
       },
       "bin": {
         "conformance": "dist/index.js"
@@ -1717,6 +1717,7 @@
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       "dev": true,
       "license": "MIT",
+      "peer": true,
       "dependencies": {
         "@typescript-eslint/scope-manager": "8.46.2",
         "@typescript-eslint/types": "8.46.2",
@@ -1935,6 +1936,7 @@
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       "dev": true,
       "license": "Apache-2.0",
+      "peer": true,
       "bin": {
         "tsgo": "bin/tsgo.js"
       },
@@ -2176,6 +2178,7 @@
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       "dev": true,
       "license": "MIT",
+      "peer": true,
       "bin": {
         "acorn": "bin/acorn"
       },
@@ -2803,6 +2806,7 @@
       "resolved": "https://registry.npmjs.org/eslint/-/eslint-9.38.0.tgz",
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       "dev": true,
+      "peer": true,
       "dependencies": {
         "@eslint-community/eslint-utils": "^4.8.0",
         "@eslint-community/regexpp": "^4.12.1",
@@ -3021,6 +3025,7 @@
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       "resolved": "https://registry.npmjs.org/express/-/express-5.1.0.tgz",
       "integrity": "sha512-DT9ck5YIRU+8GYzzU5kT3eHGA5iL+1Zd0EutOmTE9Dtk+Tvuzd23VBU+ec7HPNSTxXYO55gPV/hq4pSBJDjFpA==",
+      "peer": true,
       "dependencies": {
         "accepts": "^2.0.0",
         "body-parser": "^2.2.0",
@@ -4159,6 +4164,7 @@
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       "dev": true,
       "license": "MIT",
+      "peer": true,
       "engines": {
         "node": ">=12"
       },
@@ -4404,6 +4410,7 @@
       "resolved": "https://registry.npmjs.org/rolldown/-/rolldown-1.0.0-beta.45.tgz",
       "integrity": "sha512-iMmuD72XXLf26Tqrv1cryNYLX6NNPLhZ3AmNkSf8+xda0H+yijjGJ+wVT9UdBUHOpKzq9RjKtQKRCWoEKQQBZQ==",
       "dev": true,
+      "peer": true,
       "dependencies": {
         "@oxc-project/types": "=0.95.0",
         "@rolldown/pluginutils": "1.0.0-beta.45"
@@ -4956,6 +4963,7 @@
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       "dev": true,
       "license": "MIT",
+      "peer": true,
       "dependencies": {
         "esbuild": "~0.25.0",
         "get-tsconfig": "^4.7.5"
@@ -5002,6 +5010,7 @@
       "resolved": "https://registry.npmjs.org/typescript/-/typescript-5.9.3.tgz",
       "integrity": "sha512-jl1vZzPDinLr9eUt3J/t7V6FgNEw9QjvBPdysz9KfQDD41fQrC2Y4vKQdiaUpFT4bXlb1RHhLpp8wtm6M5TgSw==",
       "dev": true,
+      "peer": true,
       "bin": {
         "tsc": "bin/tsc",
         "tsserver": "bin/tsserver"
@@ -5089,6 +5098,7 @@
       "resolved": "https://registry.npmjs.org/vite/-/vite-7.1.12.tgz",
       "integrity": "sha512-ZWyE8YXEXqJrrSLvYgrRP7p62OziLW7xI5HYGWFzOvupfAlrLvURSzv/FyGyy0eidogEM3ujU+kUG1zuHgb6Ug==",
       "dev": true,
+      "peer": true,
       "dependencies": {
         "esbuild": "^0.25.0",
         "fdir": "^6.5.0",
@@ -5305,10 +5315,11 @@
       }
     },
     "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 fc781d9..df74abf 100644
--- a/package.json
+++ b/package.json
@@ -50,6 +50,6 @@
     "eventsource-parser": "^3.0.6",
     "express": "^5.1.0",
     "jose": "^6.1.2",
-    "zod": "^3.25.76"
+    "zod": "^4.1.13"
   }
 }