diff --git a/package-lock.json b/package-lock.json
index 70769c3..2bf1305 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -12,7 +12,7 @@
         "@map-colonies/mc-priority-queue": "^8.2.1",
         "@map-colonies/types": "^1.4.0",
         "geojson": "^0.5.0",
-        "zod": "^3.24.1"
+        "zod": "^4.1.8"
       },
       "devDependencies": {
         "@commitlint/cli": "^19.6.1",
@@ -36,6 +36,9 @@
         "tsc-alias": "^1.8.10",
         "typedoc": "^0.27.6",
         "typescript": "^5.7.2"
+      },
+      "engines": {
+        "node": ">=18.0.0"
       }
     },
     "node_modules/@ampproject/remapping": {
@@ -15495,9 +15498,9 @@
       }
     },
     "node_modules/zod": {
-      "version": "3.24.1",
-      "resolved": "https://registry.npmjs.org/zod/-/zod-3.24.1.tgz",
-      "integrity": "sha512-muH7gBL9sI1nciMZV67X5fTKKBLtwpZ5VBp1vsOQzj1MhrBZ4wlVCm3gedKZWLp0Oyel8sIGfeiz54Su+OVT+A==",
+      "version": "4.1.8",
+      "resolved": "https://registry.npmjs.org/zod/-/zod-4.1.8.tgz",
+      "integrity": "sha512-5R1P+WwQqmmMIEACyzSvo4JXHY5WiAFHRMg+zBZKgKS+Q1viRa0C1hmUKtHltoIFKtIdki3pRxkmpP74jnNYHQ==",
       "license": "MIT",
       "funding": {
         "url": "https://github.com/sponsors/colinhacks"
diff --git a/package.json b/package.json
index 536c963..20f1081 100644
--- a/package.json
+++ b/package.json
@@ -73,6 +73,6 @@
     "@map-colonies/mc-priority-queue": "^8.2.1",
     "@map-colonies/types": "^1.4.0",
     "geojson": "^0.5.0",
-    "zod": "^3.24.1"
+    "zod": "^4.1.8"
   }
 }