diff --git a/tests/Datasets/Periods.php b/tests/Datasets/Periods.php
index 66e9bcb..2536d28 100644
--- a/tests/Datasets/Periods.php
+++ b/tests/Datasets/Periods.php
@@ -20,10 +20,10 @@
     ];
 
     // todo: I don't see how this one could ever have worked. TBI…
-//        yield '1 month' => [ // P1M , but P30D vs P28D
-//            Period::make('2019-04-01', '2019-04-30', Precision::MONTH()),
-//            Period::make('2019-02-01', '2019-02-28', Precision::MONTH()),
-//        ];
+    //        yield '1 month' => [ // P1M , but P30D vs P28D
+    //            Period::make('2019-04-01', '2019-04-30', Precision::MONTH()),
+    //            Period::make('2019-02-01', '2019-02-28', Precision::MONTH()),
+    //        ];
 
     yield '1 day' => [ // P1D , but but different days
         Period::make('2019-04-23', '2019-04-23', Precision::DAY()),