diff --git a/package.json b/package.json
index f9984a2dcd..25338adcb1 100644
--- a/package.json
+++ b/package.json
@@ -101,7 +101,7 @@
   "scripts": {
     "start": "yarn serve",
     "serve": "webpack serve --config webpack.dev.js",
-    "prepare": "./scripts/prepare.sh",
+    "prepare": "node ./scripts/prepare.js",
     "build:development": "webpack --config webpack.dev.js",
     "build:production": "webpack --config webpack.prod.js",
     "lint": "eslint \"src/\"",
diff --git a/scripts/prepare.js b/scripts/prepare.js
new file mode 100755
index 0000000000..898b105e2f
--- /dev/null
+++ b/scripts/prepare.js
@@ -0,0 +1,12 @@
+const { execSync } = require('child_process');
+
+/**
+ * The npm `prepare` script needs to run a build to support installing
+ * a package from git repositories (this is dumb but a limitation of how
+ * npm behaves). We don't want to run these in CI though because
+ * building is slow so this script will skip the build when the
+ * `SKIP_PREPARE` environment variable has been set.
+ */
+if (!process.env.SKIP_PREPARE) {
+    execSync('webpack --config webpack.prod.js', { stdio: 'inherit' });
+}
diff --git a/scripts/prepare.sh b/scripts/prepare.sh
deleted file mode 100755
index bde12b36a5..0000000000
--- a/scripts/prepare.sh
+++ /dev/null
@@ -1,5 +0,0 @@
-#!/usr/bin/env bash
-
-if [ -z "${SKIP_PREPARE}" ]; then
-    webpack --config webpack.prod.js
-fi