diff --git a/src/shadowbox/webpack.config.js b/src/shadowbox/webpack.config.js
index 10eaeedd1..894bb8ebe 100644
--- a/src/shadowbox/webpack.config.js
+++ b/src/shadowbox/webpack.config.js
@@ -31,7 +31,9 @@ const config = {
   },
   plugins: [
     // Used by server/version.ts.
-    process.env.SB_VERSION ? new webpack.DefinePlugin({'__VERSION__': JSON.stringify(process.env.SB_VERSION)}): undefined,
+    process.env.VERSION
+      ? new webpack.DefinePlugin({__VERSION__: JSON.stringify(process.env.VERSION)})
+      : undefined,
     // WORKAROUND: some of our (transitive) dependencies use node-gently, which hijacks `require`.
     // Setting global.GENTLY to false makes these dependencies use standard require.
     new webpack.DefinePlugin({'global.GENTLY': false}),