diff --git a/t/db_dependent/Circulation.t b/t/db_dependent/Circulation.t
index 307db1d8a9..f37c3b8186 100755
--- a/t/db_dependent/Circulation.t
+++ b/t/db_dependent/Circulation.t
@@ -2464,8 +2464,8 @@ subtest 'AddIssue & illrequests.due_date' => sub {
 
     set_userenv($library);
 
-    my $custom_date_due = '9999-12-18 12:34:56';
-    my $expected_date_due = '9999-12-18 23:59:00';
+    my $custom_date_due = '4999-12-18 12:34:56';
+    my $expected_date_due = '4999-12-18 23:59:00';
     my $illrequest = Koha::ILL::Request->new({
         borrowernumber => $patron->borrowernumber,
         biblio_id => $item->biblionumber,
@@ -2478,8 +2478,8 @@ subtest 'AddIssue & illrequests.due_date' => sub {
 
     $patron = $builder->build_object( { class => 'Koha::Patrons' } );
     $item = $builder->build_sample_item();
-    $custom_date_due = '9999-12-19';
-    $expected_date_due = '9999-12-19 23:59:00';
+    $custom_date_due = '4999-12-19';
+    $expected_date_due = '4999-12-19 23:59:00';
     $illrequest = Koha::ILL::Request->new({
         borrowernumber => $patron->borrowernumber,
         biblio_id => $item->biblionumber,
diff --git a/t/db_dependent/Circulation/dateexpiry.t b/t/db_dependent/Circulation/dateexpiry.t
index 79ba9e0a02..f992219687 100755
--- a/t/db_dependent/Circulation/dateexpiry.t
+++ b/t/db_dependent/Circulation/dateexpiry.t
@@ -124,7 +124,7 @@ sub calc_date_due {
     is( ref $d eq "DateTime" && $d->mdy() =~ /^\d+/, 1, "CalcDateDue with expiry tomorrow" );
 
     # fourth test far future
-    $patron->dateexpiry('9876-12-31')->store;
+    $patron->dateexpiry('4999-12-31')->store;
     my $t1 = time;
     $d = C4::Circulation::CalcDateDue( $today, $item->effective_itemtype, $branch->{branchcode}, $patron );
     my $t2 = time;