diff --git a/tests/unit/Support/Calendar/Periodicity/BimonthlyTest.php b/tests/unit/Support/Calendar/Periodicity/BimonthlyTest.php
index 448ec9d07a..aab0e7714e 100644
--- a/tests/unit/Support/Calendar/Periodicity/BimonthlyTest.php
+++ b/tests/unit/Support/Calendar/Periodicity/BimonthlyTest.php
@@ -44,7 +44,7 @@ class BimonthlyTest extends IntervalTestCase
     public static function provideIntervals(): array
     {
         return [
-            new IntervalProvider(Carbon::now(), Carbon::now()->addMonths(2)),
+            new IntervalProvider(Carbon::now(), Carbon::now()->addMonthsNoOverflow(2)),
             new IntervalProvider(Carbon::parse('2019-01-29'), Carbon::parse('2019-03-29')),
             new IntervalProvider(Carbon::parse('2018-12-30'), Carbon::parse('2019-02-28')),
             new IntervalProvider(Carbon::parse('2018-12-31'), Carbon::parse('2019-02-28')),
diff --git a/tests/unit/Support/Calendar/Periodicity/QuarterlyTest.php b/tests/unit/Support/Calendar/Periodicity/QuarterlyTest.php
index 3d4b010e7f..82c34eb697 100644
--- a/tests/unit/Support/Calendar/Periodicity/QuarterlyTest.php
+++ b/tests/unit/Support/Calendar/Periodicity/QuarterlyTest.php
@@ -45,7 +45,7 @@ class QuarterlyTest extends IntervalTestCase
     public static function provideIntervals(): array
     {
         return [
-            new IntervalProvider(Carbon::now(), Carbon::now()->addMonths(3)),
+            new IntervalProvider(Carbon::now(), Carbon::now()->addMonthsNoOverflow(3)),
             new IntervalProvider(Carbon::parse('2019-01-29'), Carbon::parse('2019-04-29')),
             new IntervalProvider(Carbon::parse('2019-01-30'), Carbon::parse('2019-04-30')),
             new IntervalProvider(Carbon::parse('2019-01-31'), Carbon::parse('2019-04-30')),