diff --git a/tools/build/build.py b/tools/build/build.py
index d0bfd87c..cb0b210c 100755
--- a/tools/build/build.py
+++ b/tools/build/build.py
@@ -100,7 +100,7 @@ def build_oxjs(downloads=False, geo=False):
         [
             'Array.js', # Ox.PATH depends on Ox.toArray
             'Collection.js', # Ox.toArray depends on Ox.slice
-            'Fallback.js', # FIXME: not clear if needed here
+            'Polyfill.js', # FIXME: not clear if needed here
             'Math.js', # Ox.MAX_LATITUDE depends on Ox.sinh
             'Object.js', # Ox.typeOf depends on Ox.hasOwn
             'String.js', # HTML.js depends on Ox.char