diff --git a/app/models/issue_query.rb b/app/models/issue_query.rb
index 8140163..6fa5e57 100644
--- a/app/models/issue_query.rb
+++ b/app/models/issue_query.rb
@@ -207,6 +207,7 @@ class IssueQuery < Query
         :values => categories.collect{|s| [s.name, s.id.to_s] }
     end
 
+    add_available_filter "parent_id", :type => :integer, :label => 'field_parent_issue'
     add_available_filter "subject", :type => :text
     add_available_filter "created_on", :type => :date_past
     add_available_filter "updated_on", :type => :date_past
diff --git a/test/unit/query_test.rb b/test/unit/query_test.rb
index 4e174e8..7107d0e 100644
--- a/test/unit/query_test.rb
+++ b/test/unit/query_test.rb
@@ -848,6 +848,67 @@ class QueryTest < ActiveSupport::TestCase
     assert_equal [issue1], find_issues_with_query(query)
   end
 
+  def test_filter_on_parent_task_id
+    user = User.find(2)
+    User.current = user
+
+    Issue.delete_all
+
+    iparent = Issue.generate!(:subject => 'Parent')
+    ichild1 = Issue.generate!(:project => iparent.project, :subject => 'Child1', :parent_issue_id => iparent.id)
+    ichild2 = Issue.generate!(:project => iparent.project, :subject => 'Child2', :parent_issue_id => iparent.id)
+    igchild = Issue.generate!(:project => iparent.project, :subject => 'Grand child', :parent_issue_id => ichild2.id)
+
+    query = IssueQuery.new(:name => '_')
+
+    # check if the filter is available for issue queries
+    assert query.available_filters.key?('parent_id')
+
+    # add the filter using the equal operator
+    query.add_filter('parent_id', '=', ["#{iparent.id}"])
+
+    issues = find_issues_with_query(query)
+    assert_equal 2, issues.size
+
+    # test the filter using the greater-or-equal operator
+    query = IssueQuery.new(:name => '_')
+    query.add_filter('parent_id', '>=', ["#{iparent.id}"])
+
+    issues = find_issues_with_query(query)
+    assert_equal 3, issues.size
+
+    # test the filter using the less-or-equal operator
+    query = IssueQuery.new(:name => '_')
+    query.add_filter('parent_id', '<=', ["#{iparent.id}"])
+
+    issues = find_issues_with_query(query)
+    assert_equal 2, issues.size
+
+    # test the filter using the between operator
+    query = IssueQuery.new(:name => '_')
+    query.add_filter('parent_id', '><', ["#{ichild2.id}", "#{igchild.id}"])
+
+    issues = find_issues_with_query(query)
+    assert_equal 1, issues.size
+
+    # test the filter using the none operator
+    query = IssueQuery.new(:name => '_')
+    query.add_filter('parent_id', '!*')
+
+    issues = find_issues_with_query(query)
+    assert_equal 1, issues.size
+
+    # test the filter using the any operator
+    query = IssueQuery.new(:name => '_')
+    query.add_filter('parent_id', '*')
+
+    issues = find_issues_with_query(query)
+    assert_equal 3, issues.size
+  ensure
+    Issue.delete_all
+    User.current = nil
+  end
+
   def test_statement_should_be_nil_with_no_filters
     q = IssueQuery.new(:name => '_')
     q.filters = {}