diff --git a/app/models/queries/work_packages.rb b/app/models/queries/work_packages.rb
index 7487bbb1ab..65f9981afa 100644
--- a/app/models/queries/work_packages.rb
+++ b/app/models/queries/work_packages.rb
@@ -76,6 +76,7 @@ module Queries::WorkPackages
   register.filter Query, filters_module::SubjectOrIdFilter
   register.filter Query, filters_module::ManualSortFilter
   register.filter Query, filters_module::RelatableFilter
+  register.filter Query, filters_module::MilestoneFilter
 
   columns_module = Queries::WorkPackages::Columns
 
diff --git a/app/models/queries/work_packages/filter/milestone_filter.rb b/app/models/queries/work_packages/filter/milestone_filter.rb
new file mode 100644
index 0000000000..60630507d1
--- /dev/null
+++ b/app/models/queries/work_packages/filter/milestone_filter.rb
@@ -0,0 +1,75 @@
+#-- encoding: UTF-8
+
+#-- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) 2012-2020 the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2017 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See docs/COPYRIGHT.rdoc for more details.
+#++
+
+class Queries::WorkPackages::Filter::MilestoneFilter < Queries::WorkPackages::Filter::WorkPackageFilter
+  include Queries::Filters::Shared::BooleanFilter
+
+  def self.key
+    :is_milestone
+  end
+
+  def available?
+    types.exists?
+  end
+
+  def dependency_class
+    '::API::V3::Queries::Schemas::BooleanFilterDependencyRepresenter'
+  end
+
+  def where
+    if positive?
+      "type_id IN (#{milestone_subselect})"
+    else
+      "type_id NOT IN (#{milestone_subselect})"
+    end
+  end
+
+  def positive?
+    (operator == '=' && values == [OpenProject::Database::DB_VALUE_TRUE]) ||
+      (operator == '!' && values == [OpenProject::Database::DB_VALUE_FALSE])
+  end
+
+  def human_name
+    I18n.t('activerecord.attributes.type.is_milestone')
+  end
+
+  private
+
+  def types
+    project.nil? ? ::Type.order(Arel.sql('position')) : project.rolled_up_types
+  end
+
+  def milestone_subselect
+    Type
+      .where(is_milestone: true)
+      .select(:id)
+      .to_sql
+  end
+end
diff --git a/spec/models/queries/work_packages/filter/milestone_filter_spec.rb b/spec/models/queries/work_packages/filter/milestone_filter_spec.rb
new file mode 100644
index 0000000000..bb758fa08c
--- /dev/null
+++ b/spec/models/queries/work_packages/filter/milestone_filter_spec.rb
@@ -0,0 +1,135 @@
+#-- copyright
+# OpenProject is an open source project management software.
+# Copyright (C) 2012-2020 the OpenProject GmbH
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2017 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See docs/COPYRIGHT.rdoc for more details.
+#++
+
+require 'spec_helper'
+
+describe Queries::WorkPackages::Filter::MilestoneFilter, type: :model do
+  it_behaves_like 'basic query filter' do
+    let(:type) { :list }
+    let(:class_key) { :is_milestone }
+
+    describe '#available?' do
+      context 'within a project' do
+        before do
+          allow(project)
+            .to receive_message_chain(:rolled_up_types, :exists?)
+            .and_return true
+        end
+
+        it 'is true' do
+          expect(instance).to be_available
+        end
+
+        it 'is false without a type' do
+          allow(project)
+            .to receive_message_chain(:rolled_up_types, :exists?)
+            .and_return false
+
+          expect(instance).to_not be_available
+        end
+      end
+
+      context 'without a project' do
+        let(:project) { nil }
+
+        before do
+          allow(Type)
+            .to receive_message_chain(:order, :exists?)
+            .and_return true
+        end
+
+        it 'is true' do
+          expect(instance).to be_available
+        end
+
+        it 'is false without a type' do
+          allow(Type)
+            .to receive_message_chain(:order, :exists?)
+            .and_return false
+
+          expect(instance).to_not be_available
+        end
+      end
+    end
+  end
+
+  it_behaves_like 'boolean query filter', scope: false do
+    let(:model) { WorkPackage.unscoped }
+    let(:attribute) { :id }
+
+    describe '#scope' do
+      context 'for the true value' do
+        let(:values) { [OpenProject::Database::DB_VALUE_TRUE] }
+
+        context 'for "="' do
+          let(:operator) { '=' }
+
+          it 'is the same as handwriting the query' do
+            expected = 'type_id IN (SELECT "types"."id" FROM "types" WHERE "types"."is_milestone" = TRUE ORDER BY position ASC)'
+
+            expect(instance.where).to eql expected
+          end
+        end
+
+        context 'for "!"' do
+          let(:operator) { '!' }
+
+          it 'is the same as handwriting the query' do
+            expected = 'type_id NOT IN (SELECT "types"."id" FROM "types" WHERE "types"."is_milestone" = TRUE ORDER BY position ASC)'
+
+            expect(instance.where).to eql expected
+          end
+        end
+      end
+
+      context 'for the false value' do
+        let(:values) { [OpenProject::Database::DB_VALUE_FALSE] }
+
+        context 'for "="' do
+          let(:operator) { '=' }
+
+          it 'is the same as handwriting the query' do
+            expected = 'type_id NOT IN (SELECT "types"."id" FROM "types" WHERE "types"."is_milestone" = TRUE ORDER BY position ASC)'
+
+            expect(instance.where).to eql expected
+          end
+        end
+
+        context 'for "!"' do
+          let(:operator) { '!' }
+
+          it 'is the same as handwriting the query' do
+            expected = 'type_id IN (SELECT "types"."id" FROM "types" WHERE "types"."is_milestone" = TRUE ORDER BY position ASC)'
+
+            expect(instance.where).to eql expected
+          end
+        end
+      end
+    end
+  end
+end