diff --git a/package-lock.json b/package-lock.json
index fec24de..f885cff 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -10,7 +10,7 @@
       "license": "MIT",
       "dependencies": {
         "@modelcontextprotocol/sdk": "^1.0.4",
-        "zod": "^3.24.1"
+        "zod": "^4.4.3"
       },
       "bin": {
         "timetree-mcp": "dist/index.js"
@@ -2568,9 +2568,9 @@
       "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"
diff --git a/package.json b/package.json
index 7e9ad40..e8674d3 100644
--- a/package.json
+++ b/package.json
@@ -23,7 +23,7 @@
   "license": "MIT",
   "dependencies": {
     "@modelcontextprotocol/sdk": "^1.0.4",
-    "zod": "^3.24.1"
+    "zod": "^4.4.3"
   },
   "devDependencies": {
     "@types/node": "^25.3.0",