diff --git a/package-lock.json b/package-lock.json
index ccddecc..93edc6b 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1204,9 +1204,9 @@
       "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": "4.4.3",
+      "resolved": "https://registry.npmjs.org/zod/-/zod-4.4.3.tgz",
+      "integrity": "sha512-ytENFjIJFl2UwYglde2jchW2Hwm4GJFLDiSXWdTrJQBIN9Fcyp7n4DhxJEiWNAJMV1/BqWfW/kkg71UDcHJyTQ==",
       "license": "MIT",
       "funding": {
         "url": "https://github.com/sponsors/colinhacks"
@@ -1258,7 +1258,7 @@
       "dependencies": {
         "@agent-wallclock/core": "*",
         "@modelcontextprotocol/sdk": "^1.12.1",
-        "zod": "^3.24.2"
+        "zod": "^4.4.3"
       },
       "bin": {
         "agent-wallclock-mcp": "dist/server.js"
diff --git a/packages/mcp/package.json b/packages/mcp/package.json
index aa433c7..d164910 100644
--- a/packages/mcp/package.json
+++ b/packages/mcp/package.json
@@ -19,7 +19,7 @@
   "dependencies": {
     "@agent-wallclock/core": "*",
     "@modelcontextprotocol/sdk": "^1.12.1",
-    "zod": "^3.24.2"
+    "zod": "^4.4.3"
   },
   "engines": {
     "node": ">=20"