diff --git a/test/unit/project_nested_set_test.rb b/test/unit/project_nested_set_test.rb
index 3ecd78512..c56330ef6 100644
--- a/test/unit/project_nested_set_test.rb
+++ b/test/unit/project_nested_set_test.rb
@@ -21,6 +21,7 @@ class ProjectNestedSetTest < ActiveSupport::TestCase
 
   def setup
     Project.delete_all
+    Tracker.delete_all
 
     @a = Project.create!(:name => 'A', :identifier => 'projecta')
     @a1 = Project.create!(:name => 'A1', :identifier => 'projecta1')