diff --git a/test/unit/issue_nested_set_concurrency_test.rb b/test/unit/issue_nested_set_concurrency_test.rb
index dd02359..7467ae2 100644
--- a/test/unit/issue_nested_set_concurrency_test.rb
+++ b/test/unit/issue_nested_set_concurrency_test.rb
@@ -27,6 +27,7 @@ class IssueNestedSetConcurrencyTest < ActiveSupport::TestCase
   self.use_transactional_fixtures = false
 
   def setup
+    skip if sqlite?
     CustomField.delete_all
   end
 
@@ -35,38 +36,60 @@ class IssueNestedSetConcurrencyTest < ActiveSupport::TestCase
   end
 
   def test_concurrency
-    skip if sqlite?
-    with_settings :notified_events => [] do
-      # Generates an issue and destroys it in order
-      # to load all needed classes before starting threads
-      i = Issue.generate!
-      i.destroy
+    # Generates an issue and destroys it in order
+    # to load all needed classes before starting threads
+    i = Issue.generate!
+    i.destroy
 
-      root = Issue.generate!
-      assert_difference 'Issue.count', 60 do
-        threads = []
-        3.times do |i|
-          threads << Thread.new(i) do
-            ActiveRecord::Base.connection_pool.with_connection do
-              begin
-                10.times do
-                  i = Issue.generate! :parent_issue_id => root.id
-                  c1 = Issue.generate! :parent_issue_id => i.id
-                  c2 = Issue.generate! :parent_issue_id => i.id
-                  c3 = Issue.generate! :parent_issue_id => i.id
-                  c2.reload.destroy
-                  c1.reload.destroy
-                end
-              rescue Exception => e
-                Thread.current[:exception] = e.message
-              end
+    root = Issue.generate!
+    assert_difference 'Issue.count', 60 do
+      threaded(3) do
+        10.times do
+          i = Issue.generate! :parent_issue_id => root.id
+          c1 = Issue.generate! :parent_issue_id => i.id
+          c2 = Issue.generate! :parent_issue_id => i.id
+          c3 = Issue.generate! :parent_issue_id => i.id
+          c2.reload.destroy
+          c1.reload.destroy
+        end
+      end
+    end
+  end
+
+  def test_concurrent_subtasks_creation
+    root = Issue.generate!
+    assert_difference 'Issue.count', 30 do
+      threaded(3) do
+        10.times do
+          Issue.generate! :parent_issue_id => root.id
+        end
+      end
+    end
+    root.reload
+    assert_equal [1, 62], [root.lft, root.rgt]
+    children_bounds = root.children.sort_by(&:lft).map {|c| [c.lft, c.rgt]}.flatten
+    assert_equal (2..61).to_a, children_bounds
+  end
+
+  private
+
+  def threaded(count, &block)
+    with_settings :notified_events => [] do
+      threads = []
+      count.times do |i|
+        threads << Thread.new(i) do
+          ActiveRecord::Base.connection_pool.with_connection do
+            begin
+              yield
+            rescue Exception => e
+              Thread.current[:exception] = e.message
             end
           end
         end
-        threads.each do |thread|
-          thread.join
-          assert_nil thread[:exception]
-        end
+      end
+      threads.each do |thread|
+        thread.join
+        assert_nil thread[:exception]
       end
     end
   end