diff --git a/.gitignore b/.gitignore
index a1d21bd..a852b7a 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,4 @@
+.idea
 .rvmrc
 .bundle
 coverage/*
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 6a5b643..69124b8 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,7 +1,14 @@
+## [next]
+
+Fixes:
+
+  - `XapianDb.database.delete_docs_of_class(klass)` now deletes docs of all descendants of `klass`, too (if tracked)
+
 ##1.3.6 (August 14th, 2015)
 
 Changes:
 
+  - The required Ruby version is now 2.0.0 since we started using keyword parameters in method definitions 
   - Ability do define and handle dependencies between blueprints (see README)
   - explicit order option for searches
 
diff --git a/README.rdoc b/README.rdoc
index 43b4bfd..51520c4 100644
--- a/README.rdoc
+++ b/README.rdoc
@@ -32,9 +32,9 @@ I tried hard but I couldn't find such a thing so I decided to write it, based on
 
 == Requirements
 
-* ruby 1.9.2 or newer
+* ruby 2.0.0 or newer
 * rails 3.0 or newer (if you want to use it with rails)
-* xapian-core and xapian-ruby binaries installed
+* xapian-core and xapian-ruby binaries 1.2.x installed
 
 == Installing xapian binaries
 
diff --git a/examples/basic.rb b/examples/basic.rb
index 87f19ca..7b03cd4 100644
--- a/examples/basic.rb
+++ b/examples/basic.rb
@@ -19,6 +19,9 @@
 # 2: Define a class which should get indexed; we define a class that
 # could be an ActiveRecord or Datamapper Domain class
 class Person
+  # If you are using inheritance hierarchies among indexed classes outside of ActiveRecord,
+  # using DescendantsTracker helps with rebuilding the Xapian index for a given class and all its subclasses.
+  extend DescendantsTracker
 
   attr_accessor :id, :name, :first_name, :date_of_birth
 
diff --git a/lib/xapian_db/database.rb b/lib/xapian_db/database.rb
index bf36155..3ca2c06 100644
--- a/lib/xapian_db/database.rb
+++ b/lib/xapian_db/database.rb
@@ -35,10 +35,19 @@ def delete_doc_with_unique_term(term)
       true
     end
 
-    # Delete all docs of a specific class
+    # Delete all docs of a specific class.
+    #
+    # If `klass` tracks its descendants, then docs of any subclasses will be deleted, too.
+    # (ActiveRecord does this by default; the gem 'descendants_tracker' offers an alternative.)
+    #
     # @param [Class] klass A class that has a {XapianDb::DocumentBlueprint} configuration
     def delete_docs_of_class(klass)
       writer.delete_document("C#{klass}")
+      if klass.respond_to? :descendants
+        klass.descendants.each do |subclass|
+          writer.delete_document("C#{subclass}")
+        end
+      end
       true
     end
 
diff --git a/spec/basic_mocks.rb b/spec/basic_mocks.rb
index 61cc92f..f8a93e6 100644
--- a/spec/basic_mocks.rb
+++ b/spec/basic_mocks.rb
@@ -9,7 +9,7 @@ def tableize
     self # not really important what we return
   end
 
-  def parameterize 
+  def parameterize
     self # not really important what we return
   end
 
@@ -24,6 +24,23 @@ def initialize(id)
   end
 end
 
+class IndexedObjectSubclass < IndexedObject
+end
+
+require 'descendants_tracker'
+class IndexedObjectDT
+  extend DescendantsTracker
+
+  attr_reader :id
+
+  def initialize(id)
+    @id = id
+  end
+end
+
+class IndexedObjectTrackedSubclass < IndexedObjectDT
+end
+
 class OtherIndexedObject
   attr_reader :id
 
diff --git a/spec/xapian_db/database_spec.rb b/spec/xapian_db/database_spec.rb
index 4d8e4d3..65dfc4f 100644
--- a/spec/xapian_db/database_spec.rb
+++ b/spec/xapian_db/database_spec.rb
@@ -73,11 +73,15 @@
         config.adapter :generic
         config.database :memory
       end
-      XapianDb::DocumentBlueprint.setup(:IndexedObject) do |blueprint|
-        blueprint.attribute :id
+      %i[ IndexedObject IndexedObjectSubclass IndexedObjectDT IndexedObjectTrackedSubclass ].each do |klass|
+        XapianDb::DocumentBlueprint.setup(klass) do |blueprint|
+          blueprint.attribute :id
+        end
       end
-      @blueprint = XapianDb::DocumentBlueprint.blueprint_for(:IndexedObject)
-      @indexer   = XapianDb::Indexer.new(XapianDb.database, @blueprint)
+      @blueprint    = XapianDb::DocumentBlueprint.blueprint_for(:IndexedObject)
+      @blueprint_dt = XapianDb::DocumentBlueprint.blueprint_for(:IndexedObjectDT)
+      @indexer    = XapianDb::Indexer.new(XapianDb.database, @blueprint)
+      @indexer_dt = XapianDb::Indexer.new(XapianDb.database, @blueprint_dt)
     end
 
     it "should delete all docs of the given class" do
@@ -99,6 +103,40 @@
 
     end
 
+    it "should delete all docs of descendant classes, too, if they are tracked" do
+
+      # Create a doc for a tracked subclass
+      obj = IndexedObjectTrackedSubclass.new(1)
+      doc = @indexer_dt.build_document_for(obj)
+      expect(XapianDb.database.store_doc(doc)).to be_truthy
+
+      XapianDb.database.commit
+      expect(XapianDb.database.size).to eq(1)
+
+      # Now delete all docs of the object's superclass
+      XapianDb.database.delete_docs_of_class(IndexedObjectDT)
+      XapianDb.database.commit
+      expect(XapianDb.database.size).to eq(0)
+
+    end
+
+    it "ignore descendant classes where no descendants tracking mechanism is employed" do
+
+      # Create a doc for a non-tracked subclass
+      obj = IndexedObjectSubclass.new(1)
+      doc = @indexer.build_document_for(obj)
+      expect(XapianDb.database.store_doc(doc)).to be_truthy
+
+      XapianDb.database.commit
+      expect(XapianDb.database.size).to eq(1)
+
+      # Now delete all docs of the object's superclass
+      XapianDb.database.delete_docs_of_class(IndexedObject)
+      XapianDb.database.commit
+      expect(XapianDb.database.size).to eq(1)
+
+    end
+
     it "must not delete docs of a different class that have a term like the name of <klass>" do
 
       class LeaveMeAlone
diff --git a/spec/xapian_db/document_blueprint_spec.rb b/spec/xapian_db/document_blueprint_spec.rb
index ab49c82..d000b2c 100644
--- a/spec/xapian_db/document_blueprint_spec.rb
+++ b/spec/xapian_db/document_blueprint_spec.rb
@@ -226,9 +226,12 @@ class InheritedIndexedObject < IndexedObject; end
     it "does replace the blueprint for a class if the class is reloaded" do
       XapianDb::DocumentBlueprint.setup(:IndexedObject)
       expect(XapianDb::DocumentBlueprint.configured_classes.size).to eq(1)
+
       # reload IndexedObject
       Object.send(:remove_const, :IndexedObject)
+      Object.send(:remove_const, :IndexedObjectSubclass)
       load File.expand_path('../../basic_mocks.rb', __FILE__)
+
       XapianDb::DocumentBlueprint.setup(:IndexedObject)
       expect(XapianDb::DocumentBlueprint.configured_classes.size).to eq(1)
     end
diff --git a/xapian_db.gemspec b/xapian_db.gemspec
index 37a187f..1e15671 100644
--- a/xapian_db.gemspec
+++ b/xapian_db.gemspec
@@ -14,7 +14,8 @@ Gem::Specification.new do |s|
   s.homepage     = %q{https://github.com/garaio/xapian_db}
   s.rdoc_options = ["--line-numbers", "--inline-source", "--title", "Xapian-DB", "--main", "README.rdoc"]
 
-  s.required_rubygems_version = ">=1.3.6"
+  s.required_ruby_version     = ">= 2.0.0"
+  s.required_rubygems_version = ">= 1.3.6"
 
   s.add_dependency "daemons", ">= 1.0.10"
 
@@ -26,8 +27,9 @@ Gem::Specification.new do |s|
   s.add_development_dependency "ruby-progressbar"
   s.add_development_dependency "resque",           ">= 1.19.0"
   s.add_development_dependency "sidekiq",          ">= 2.13.0"
-  s.add_development_dependency "xapian-ruby",      "= 1.2.21"
+  s.add_development_dependency "xapian-ruby",      "= 1.2.22"
   s.add_development_dependency "pry-rails"
+  s.add_development_dependency "descendants_tracker"
 
   s.files         = Dir.glob("lib/**/*") + Dir.glob("tasks/*") + Dir.glob("xapian_source/*") + %w(LICENSE README.rdoc CHANGELOG.md Rakefile)
   s.require_path  = "lib"