diff --git a/packages/lib/.gitignore b/packages/lib/.gitignore
new file mode 100644
index 00000000..922aef1f
--- /dev/null
+++ b/packages/lib/.gitignore
@@ -0,0 +1 @@
+src/data/message_validate.js
diff --git a/packages/lib/.npmignore b/packages/lib/.npmignore
new file mode 100644
index 00000000..e69de29b
diff --git a/packages/lib/package.json b/packages/lib/package.json
index 635d1599..ce052530 100644
--- a/packages/lib/package.json
+++ b/packages/lib/package.json
@@ -4,6 +4,10 @@
   "version": "2.0.0-alpha.13",
   "repository": "https://github.com/clusterio/clusterio",
   "license": "MIT",
+  "scripts": {
+    "prepare": "pnpm run compile_validator",
+    "compile_validator": "node scripts/compile_validator.js"
+  },
   "browser": "browser.js",
   "keywords": [
     "factorio"
diff --git a/packages/lib/scripts/compile_validator.js b/packages/lib/scripts/compile_validator.js
new file mode 100644
index 00000000..bc90dcf4
--- /dev/null
+++ b/packages/lib/scripts/compile_validator.js
@@ -0,0 +1,28 @@
+"use strict";
+const fs = require("fs-extra");
+const path = require("path");
+const Ajv = require("ajv");
+const standaloneCode = require("ajv/dist/standalone").default;
+
+/* eslint-disable node/no-sync */
+
+// Provide an empty file for message_core to load
+fs.outputFileSync(path.join(__dirname, "../src/data/message_validate.js"), "");
+
+const { Message } = require("../src/data/messages_core");
+
+const ajv = new Ajv({
+	allowUnionTypes: true,
+	strict: "log",
+	strictTuples: false,
+	verbose: true,
+	code: {
+		source: true,
+	},
+});
+const validate = ajv.compile(Message.jsonSchema);
+let moduleCode = standaloneCode(ajv, validate);
+fs.outputFileSync(
+	path.join(__dirname, "../src/data/message_validate.js"),
+	`// generated by scripts/compile_validator.js\n/* eslint-disable */\n${moduleCode}`
+);
diff --git a/packages/lib/src/data/messages_core.js b/packages/lib/src/data/messages_core.js
index 14e090f9..beda4502 100644
--- a/packages/lib/src/data/messages_core.js
+++ b/packages/lib/src/data/messages_core.js
@@ -1,5 +1,6 @@
+// Note: Run compile_validator script after making changes to this file.
 "use strict";
-const libSchema = require("../schema");
+const message_validate = require("./message_validate.js");
 
 
 /** @memberof module:lib */
@@ -851,7 +852,7 @@ Message.jsonSchema = {
 		MessageDisconnect.jsonSchema,
 	],
 };
-Message.validate = libSchema.compile(Message.jsonSchema);
+Message.validate = message_validate;
 
 /** @memberof module:lib */
 class PingRequest {