diff --git a/ts/util/context.ts b/ts/util/context.ts
index a18295ba3..8179b590b 100644
--- a/ts/util/context.ts
+++ b/ts/util/context.ts
@@ -22,12 +22,18 @@
  */
 
 declare const process: { platform: string };
+declare const exports: object;
 
 /**
  * True if there is a window object
  */
 export const hasWindow = typeof window !== 'undefined';
 
+/**
+ * True if used from the cjs directory, false for mjs directory
+ */
+export const isCJS = typeof exports !== 'undefined';
+
 /**
  * The browsers window and document objects, if any
  */
@@ -75,6 +81,6 @@ export const context = {
 if (context.os === 'Windows') {
   context.path = (file: string) =>
     file.match(/^[/\\]?[a-zA-Z]:[/\\]/)
-      ? 'file://' + file.replace(/\\/g, '/').replace(/^\//, '')
+      ? (isCJS ? '' : 'file://') + file.replace(/\\/g, '/').replace(/^\//, '')
       : file.replace(/^\//, 'file:///');
 }