diff --git a/package.json b/package.json
index 00aec30f..f2170da9 100644
--- a/package.json
+++ b/package.json
@@ -3,7 +3,7 @@
     "version": "0.1.0",
     "private": true,
     "dependencies": {
-        "@pybricks/mpy-cross-4": "^2.0.0",
+        "@pybricks/mpy-cross-v4": "^1.0.0",
         "@testing-library/jest-dom": "^5.8.0",
         "@testing-library/react": "^10.0.4",
         "@testing-library/user-event": "^10.3.4",
@@ -40,7 +40,7 @@
         "xterm-addon-fit": "^0.3.0"
     },
     "scripts": {
-        "prepare": "mkdir -p public/static/js && cp node_modules/@pybricks/mpy-cross-4/build-wasm/mpy-cross.wasm public/static/js/",
+        "prepare": "mkdir -p public/static/js && cp node_modules/@pybricks/mpy-cross-v4/build/mpy-cross.wasm public/static/js/",
         "start": "react-scripts start",
         "build": "react-scripts build",
         "test": "react-scripts test --env=./test-env.js",
diff --git a/src/actions/mpy.ts b/src/actions/mpy.ts
index 6fb4305e..e6be0b31 100644
--- a/src/actions/mpy.ts
+++ b/src/actions/mpy.ts
@@ -1,7 +1,7 @@
 // SPDX-License-Identifier: MIT
 // Copyright (c) 2020 The Pybricks Authors
 
-import { compile as mpyCrossCompile } from '@pybricks/mpy-cross-4';
+import { compile as mpyCrossCompile } from '@pybricks/mpy-cross-v4';
 import { Action } from 'redux';
 import { ThunkAction } from 'redux-thunk';
 
diff --git a/yarn.lock b/yarn.lock
index f451e5ec..7d71c82c 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -1254,10 +1254,10 @@
   resolved "https://registry.yarnpkg.com/@popperjs/core/-/core-2.4.0.tgz#0e1bdf8d021e7ea58affade33d9d607e11365915"
   integrity sha512-NMrDy6EWh9TPdSRiHmHH2ye1v5U0gBD7pRYwSwJvomx7Bm4GG04vu63dYiVzebLOx2obPpJugew06xVP0Nk7hA==
 
-"@pybricks/mpy-cross-4@^2.0.0":
-  version "2.0.0"
-  resolved "https://npm.pkg.github.com/download/@pybricks/mpy-cross-4/2.0.0/ee1d8da09629b14ea43bc6ac7a685b48fe191404958215e3b267478c6d750aa8#4bdf4c397652ca69ecf7ecb0749d76afc928f39b"
-  integrity sha512-qSUDm8WMCq/ZH0wdWpgnR9fHDBnLsTQ+6CNc1ARX4orD0Wezpp/N34ya45G2RGyy6dFB/YAqYcK/daGhb6Ka8Q==
+"@pybricks/mpy-cross-v4@^1.0.0":
+  version "1.0.0"
+  resolved "https://npm.pkg.github.com/download/@pybricks/mpy-cross-v4/1.0.0/1961a986e77b302cb05c3e6dc03feefe06292488a05d23ea32d27e2f625e782a#82633377519ba904dbd3e0f700a4b38f8212a80f"
+  integrity sha512-2fWyh+ja+N6jje1o1WUOiCyciWERuXGZkLmYKdanluqtQuJcteCE6mzndgs5rxH4DuknKKmxjHuYwwzdDO0yDw==
 
 "@redux-saga/core@^1.1.3":
   version "1.1.3"