diff --git a/.github/workflows/npm.yml b/.github/workflows/npm.yml
new file mode 100644
index 00000000..41b6441b
--- /dev/null
+++ b/.github/workflows/npm.yml
@@ -0,0 +1,35 @@
+name: Build npm package
+on: push
+jobs:
+  build:
+    if: contains(github.event.head_commit.message, '🔖')
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      packages: write
+    steps:
+      - uses: actions/checkout@v3
+      # Setup .npmrc file to use GitHub Packages
+      - uses: actions/setup-node@v3
+        with:
+          node-version: '10.x'
+          registry-url: 'https://npm.pkg.github.com'
+          # Defaults to the user or organization that owns the workflow file
+          scope: '@screeps'
+      - name: Install
+        run: npm ci
+        env:
+          NODE_AUTH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+      - name: Publish (github)
+        run: npm publish
+        env:
+          NODE_AUTH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+      - uses: actions/setup-node@v3
+        with:
+          node-version: '10.x'
+          registry-url: 'https://registry.npmjs.org'
+          scope: '@screeps'
+      - name: Publish (npmjs)
+        run: npm publish
+        env:
+          NODE_AUTH_TOKEN: ${{ secrets.NPMJS_TOKEN }}
diff --git a/.npmignore b/.npmignore
index 24531a47..127c146e 100644
--- a/.npmignore
+++ b/.npmignore
@@ -2,6 +2,7 @@
 node_modules
 .idea
 .run
+.github
 build/config.gypi
 src/local-config.js
 dist/core
diff --git a/package-lock.json b/package-lock.json
index 4272c0f5..24cd7335 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,6 +1,6 @@
 {
   "name": "@screeps/engine",
-  "version": "4.2.16",
+  "version": "4.2.17-rc1",
   "lockfileVersion": 1,
   "requires": true,
   "dependencies": {
@@ -36,9 +36,9 @@
       }
     },
     "@screeps/pathfinding": {
-      "version": "0.4.16",
-      "resolved": "https://registry.npmjs.org/@screeps/pathfinding/-/pathfinding-0.4.16.tgz",
-      "integrity": "sha1-0dCKmij21UrDzx8qV6X+ppAuVpc=",
+      "version": "0.4.17",
+      "resolved": "https://registry.npmjs.org/@screeps/pathfinding/-/pathfinding-0.4.17.tgz",
+      "integrity": "sha512-W8z4jkKe+PHtWWNZ3Q4Jy/BtK90hqe/THt1bXlFNlgCZrZxMh5ckAsKfa4v1jSHX1QE35BkQYH0yxYt5Q+o6rw==",
       "requires": {
         "heap": "0.2.5"
       }
@@ -2226,7 +2226,7 @@
     "heap": {
       "version": "0.2.5",
       "resolved": "https://registry.npmjs.org/heap/-/heap-0.2.5.tgz",
-      "integrity": "sha1-cTtlWQ68xA/L7q9V6FFpQJKzmvE="
+      "integrity": "sha512-G7HLD+WKcrOyJP5VQwYZNC3Z6FcQ7YYjEFiFoIj8PfEr73mu421o8B1N5DKUcc8K37EsJ2XXWA8DtrDz/2dReg=="
     },
     "home-or-tmp": {
       "version": "2.0.0",
@@ -2768,7 +2768,8 @@
     "natives": {
       "version": "1.1.6",
       "resolved": "https://registry.npmjs.org/natives/-/natives-1.1.6.tgz",
-      "integrity": "sha512-6+TDFewD4yxY14ptjKaS63GVdtKiES1pTPyxn9Jb0rBqPMZ7VcCiooEhPNsr+mqHtMGxa/5c/HhcC4uPEUw/nA=="
+      "integrity": "sha512-6+TDFewD4yxY14ptjKaS63GVdtKiES1pTPyxn9Jb0rBqPMZ7VcCiooEhPNsr+mqHtMGxa/5c/HhcC4uPEUw/nA==",
+      "dev": true
     },
     "nice-try": {
       "version": "1.0.5",
diff --git a/package.json b/package.json
index 48093667..16749126 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@screeps/engine",
-  "version": "4.2.16",
+  "version": "4.2.17-rc1",
   "bin": {
     "screeps-engine-main": "dist/main.js",
     "screeps-engine-runner": "dist/runner.js",
@@ -8,10 +8,11 @@
   },
   "main": "dist/index.js",
   "scripts": {
-    "test": "cross-env DRIVER_MODULE=@screeps/driver jasmine"
+    "test": "cross-env DRIVER_MODULE=@screeps/driver jasmine",
+    "prepublish": "gulp"
   },
   "dependencies": {
-    "@screeps/pathfinding": "^0.4.16",
+    "@screeps/pathfinding": "^0.4.17",
     "bulk-require": "^0.2.1",
     "cross-env": "^5.2.0",
     "lodash": "3.10.1",
@@ -41,5 +42,8 @@
       "transform-es2015-destructuring",
       "transform-strict-mode"
     ]
+  },
+  "browser": {
+    "@screeps/core": "@screeps/simcore"
   }
 }
diff --git a/src/game/game.js b/src/game/game.js
index f9506004..579a2b49 100644
--- a/src/game/game.js
+++ b/src/game/game.js
@@ -6,7 +6,8 @@
         C = driver.constants,
         map = require('./map'),
         market = require('./market'),
-        customPrototypes = require('./custom-prototypes');
+        customPrototypes = require('./custom-prototypes'),
+        system = { Function: { bind: Function.bind } };
 
     var findCacheFn = {
         [C.FIND_CREEPS]: (i) => !i.spawning,
@@ -505,7 +506,7 @@
                 !_.isObject(runCodeCache[userId].globals.require.cache.main) || !_.isFunction(
                     runCodeCache[userId].globals.require.cache.main.loop)) {
 
-                runCodeCache[userId].globals.require = requireFn.bind(runCodeCache[userId]);
+                runCodeCache[userId].globals.require = system.Function.bind.call(requireFn, runCodeCache[userId]);
                 runCodeCache[userId].globals.require.cache = {lodash: runCodeCache[userId].globals._};
                 runCodeCache[userId].globals.require.timestamp = runCodeCache[userId].runtimeData.userCodeTimestamp;
             }
diff --git a/src/utils.js b/src/utils.js
index 7c25b460..35c03a83 100644
--- a/src/utils.js
+++ b/src/utils.js
@@ -15,7 +15,7 @@ catch(e) {}
 exports.getDriver = function getDriver() {
     driver = typeof process != 'undefined' && process.env.DRIVER_MODULE ?
         require(process.env.DRIVER_MODULE) :
-        require('./core/index');
+        require('@screeps/core');
     loadDriver();
     return driver;
 };