diff --git a/test/number_format_test.dart b/test/number_format_test.dart
index b9e4627..8c1d61f 100644
--- a/test/number_format_test.dart
+++ b/test/number_format_test.dart
@@ -85,7 +85,7 @@
     var testLength = (testFormats.length * 3) + 1;
     var list = mainList.take(testLength).iterator;
     list.moveNext();
-    mainList = mainList.skip(testLength);
+    mainList = mainList.skip(testLength).toList();
     if (locale == list.current) {
       testAgainstIcu(locale, testFormats, list);
     }