diff --git a/modules/js/src/make_umd.py b/modules/js/src/make_umd.py
index bed6ee9bcc..1096a8eb31 100644
--- a/modules/js/src/make_umd.py
+++ b/modules/js/src/make_umd.py
@@ -95,7 +95,7 @@ def make_umd(opencvjs, cvjs):
     root.cv = factory();
   } else if (typeof importScripts === 'function') {
     // Web worker
-    root.cv = factory;
+    root.cv = factory();
   } else {
     // Other shells, e.g. d8
     root.cv = factory();