diff --git a/lib/redmine/nested_set/issue_nested_set.rb b/lib/redmine/nested_set/issue_nested_set.rb
index afbe6b9..8753f25 100644
--- a/lib/redmine/nested_set/issue_nested_set.rb
+++ b/lib/redmine/nested_set/issue_nested_set.rb
@@ -183,6 +183,16 @@ module Redmine
           end
         end
 
+        def rebuild_single_tree!(root_id)
+          root = Issue.where(:parent_id => nil).find(root_id)
+          transaction do
+            where(root_id: root_id).reorder(:id).lock.ids
+            where(root_id: root_id).update_all(:lft => nil, :rgt => nil)
+            where(root_id: root_id, parent_id: nil).update_all(["lft = ?, rgt = ?", 1, 2])
+            rebuild_nodes(root_id)
+          end
+        end
+
         private
 
         def rebuild_nodes(parent_id = nil)
diff --git a/test/unit/issue_nested_set_test.rb b/test/unit/issue_nested_set_test.rb
index 88f65d3..4062839 100644
--- a/test/unit/issue_nested_set_test.rb
+++ b/test/unit/issue_nested_set_test.rb
@@ -306,4 +306,23 @@ class IssueNestedSetTest < ActiveSupport::TestCase
     assert_equal ic2, ic4.parent
     assert ic5.root?
   end
+
+  def test_rebuild_single_tree
+    i1 = Issue.generate!
+    i2 = i1.generate_child!
+    i3 = i1.generate_child!
+    Issue.update_all(:lft => 7, :rgt => 7)
+
+    Issue.rebuild_single_tree!(i1.id)
+
+    i1.reload
+    assert_equal [1, 6], [i1.lft, i1.rgt]
+    i2.reload
+    assert_equal [2, 3], [i2.lft, i2.rgt]
+    i3.reload
+    assert_equal [4, 5], [i3.lft, i3.rgt]
+
+    other = Issue.find(1)
+    assert_equal [7, 7], [other.lft, other.rgt]
+  end
 end