diff --git a/server/build/root-module-relative-path.js b/server/build/root-module-relative-path.js
index 84de5c25..54557a81 100644
--- a/server/build/root-module-relative-path.js
+++ b/server/build/root-module-relative-path.js
@@ -5,7 +5,9 @@
 // This function returns paths relative to the top-level 'node_modules'
 // directory found in the path. If none is found, returns the complete path.
 
-const RELATIVE_START = 'node_modules/'
+import { sep } from 'path'
+
+const RELATIVE_START = `node_modules${sep}`
 
 // Pass in the module's `require` object since it's module-specific.
 export default (moduleRequire) => (path) => {