diff --git a/test/intl402/Temporal/PlainDate/prototype/since/leap-year-since.js b/test/intl402/Temporal/PlainDate/prototype/since/leap-year-since.js
new file mode 100644
index 00000000000..3921ecc4761
--- /dev/null
+++ b/test/intl402/Temporal/PlainDate/prototype/since/leap-year-since.js
@@ -0,0 +1,15 @@
+// Copyright (C) 2025 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.plaindate.prototype.since
+description: Subtracting a date in a leap year from a date in a common year should work
+includes: [temporalHelpers.js]
+features: [Temporal]
+---*/
+
+const calendar = 'chinese';
+const a = new Temporal.PlainDate(2016, 7, 31, calendar);
+const b = new Temporal.PlainDate(2017, 7, 31, calendar);
+TemporalHelpers.assertDuration(b.since(a, { largestUnit: 'years' }),
+  0, 12, 0, 11, 0, 0, 0, 0, 0, 0);
diff --git a/test/intl402/Temporal/PlainDate/prototype/until/leap-year-until.js b/test/intl402/Temporal/PlainDate/prototype/until/leap-year-until.js
new file mode 100644
index 00000000000..47c54906469
--- /dev/null
+++ b/test/intl402/Temporal/PlainDate/prototype/until/leap-year-until.js
@@ -0,0 +1,16 @@
+// Copyright (C) 2025 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.plaindate.prototype.until
+description: Subtracting a date in a leap year from a date in a common year should work
+includes: [temporalHelpers.js]
+features: [Temporal]
+---*/
+
+const calendar = 'hebrew';
+const a = new Temporal.PlainDate(1967, 2, 28, calendar);
+const b = new Temporal.PlainDate(1968, 3, 1, calendar);
+TemporalHelpers.assertDuration(a.until(b, { largestUnit: 'years' }),
+  0, 12, 0, 13, 0, 0, 0, 0, 0, 0);
+