diff --git a/app/models/ticket/number/date.rb b/app/models/ticket/number/date.rb
index ce92976f9..9db958c4b 100644
--- a/app/models/ticket/number/date.rb
+++ b/app/models/ticket/number/date.rb
@@ -82,12 +82,12 @@ module Ticket::Number::Date
     ticket              = nil
 
     # probe format
-    string.scan(/#{Regexp.quote(ticket_hook)}#{Regexp.quote(ticket_hook_divider)}(#{system_id}\d{2,48})/i) {
+    string.scan(/#{Regexp.quote(ticket_hook)}#{Regexp.quote(ticket_hook_divider)}(\d{4,10}#{system_id}\d{2,40})/i) {
       ticket = Ticket.find_by(number: $1)
       break if ticket
     }
     if !ticket
-      string.scan(/#{Regexp.quote(ticket_hook)}\s{0,2}(#{system_id}\d{2,48})/i) {
+      string.scan(/#{Regexp.quote(ticket_hook)}\s{0,2}(\d{4,10}#{system_id}\d{2,40})/i) {
         ticket = Ticket.find_by(number: $1)
         break if ticket
       }
diff --git a/test/unit/ticket_test.rb b/test/unit/ticket_test.rb
index 9a6709e72..ec07825d3 100644
--- a/test/unit/ticket_test.rb
+++ b/test/unit/ticket_test.rb
@@ -307,6 +307,41 @@ class TicketTest < ActiveSupport::TestCase
 
   end
 
+  test 'ticket followup number check' do
+
+    origin_backend = Setting.get('ticket_number')
+    Setting.set('ticket_number', 'Ticket::Number::Increment')
+
+    ticket1 = Ticket.create(
+      title: 'subject test 1234-1',
+      group: Group.lookup(name: 'Users'),
+      customer_id: 2,
+      state: Ticket::State.lookup(name: 'new'),
+      priority: Ticket::Priority.lookup(name: '2 normal'),
+      updated_by_id: 1,
+      created_by_id: 1,
+    )
+    assert_equal('subject test 1234-1', ticket1.title)
+    assert_equal("ABC subject test 1 [Ticket##{ticket1.number}]", ticket1.subject_build('ABC subject test 1'))
+    assert_equal(ticket1.id, Ticket::Number.check("Re: Help [Ticket##{ticket1.number}]").id)
+
+    Setting.set('ticket_number', 'Ticket::Number::Date')
+    ticket1 = Ticket.create(
+      title: 'subject test 1234-2',
+      group: Group.lookup(name: 'Users'),
+      customer_id: 2,
+      state: Ticket::State.lookup(name: 'new'),
+      priority: Ticket::Priority.lookup(name: '2 normal'),
+      updated_by_id: 1,
+      created_by_id: 1,
+    )
+    assert_equal('subject test 1234-2', ticket1.title)
+    assert_equal("ABC subject test 1 [Ticket##{ticket1.number}]", ticket1.subject_build('ABC subject test 1'))
+    assert_equal(ticket1.id, Ticket::Number.check("Re: Help [Ticket##{ticket1.number}]").id)
+
+    Setting.set('ticket_number', origin_backend)
+  end
+
   test 'article attachment helper 1' do
 
     ticket1 = Ticket.create(