diff --git a/examples/full.chapters.json b/examples/full.chapters.json
index 1123d13..44ea17e 100644
--- a/examples/full.chapters.json
+++ b/examples/full.chapters.json
@@ -1,16 +1,22 @@
 [
   {
-    "slug": "1",
+    "slug": "1-юникод",
     "title": "Chapter 1",
     "chapters": [
 
     ]
   },
   {
-    "slug": "2-юникод",
+    "slug": "2",
     "title": "Chapter 2",
     "chapters": [
+      {
+        "slug": "2-nested",
+        "title": "Chapter 2.1",
+        "chapters": [
 
+        ]
+      }
     ]
   }
 ]
diff --git a/examples/full.gmi b/examples/full.gmi
index 3c77dd7..c7fdb05 100644
--- a/examples/full.gmi
+++ b/examples/full.gmi
@@ -27,6 +27,10 @@ Chapter 1 paragraph text
 
 Chapter 2 paragraph text
 
+### Chapter 2.1
+
+Chapter 2.1 paragraph text
+
 
 
 ## Related articles
diff --git a/examples/full.html b/examples/full.html
index 78c5109..321e136 100644
--- a/examples/full.html
+++ b/examples/full.html
@@ -63,18 +63,24 @@ The Rty
 </div>
 </div>
 </div>
-<h2 id="chapter-1">Chapter 1</h2>
+<h2 id="chapter-1-юникод">Chapter 1</h2>
 <p>
 <span>
 Chapter 1 paragraph text
 </span>
 </p>
-<h2 id="chapter-2-юникод">Chapter 2</h2>
+<h2 id="chapter-2">Chapter 2</h2>
 <p>
 <span>
 Chapter 2 paragraph text
 </span>
 </p>
+<h3 id="chapter-2-nested">Chapter 2.1</h3>
+<p>
+<span>
+Chapter 2.1 paragraph text
+</span>
+</p>
 <div>
 <hr/>
 <h2>Related articles</h2>
diff --git a/examples/full.repub b/examples/full.repub
index dc27595..d93bc8b 100644
--- a/examples/full.repub
+++ b/examples/full.repub
@@ -33,7 +33,7 @@ end
 
 
 
-article.chapter '1', 'Chapter 1' do |chapter|
+article.chapter '1-юникод', 'Chapter 1' do |chapter|
   chapter.paragraph do |paragraph|
     paragraph.text 'Chapter 1 paragraph text'
   end
@@ -41,10 +41,18 @@ end
 
 
 
-article.chapter '2-юникод', 'Chapter 2' do |chapter|
+article.chapter '2', 'Chapter 2' do |chapter|
   chapter.paragraph do |paragraph|
     paragraph.text 'Chapter 2 paragraph text'
   end
+
+
+
+  chapter.chapter 'nested', 'Chapter 2.1' do |chapter|
+    chapter.paragraph do |paragraph|
+      paragraph.text 'Chapter 2.1 paragraph text'
+    end
+  end
 end
 
 
diff --git a/examples/full.summary.txt b/examples/full.summary.txt
index 9374b10..5227adc 100644
--- a/examples/full.summary.txt
+++ b/examples/full.summary.txt
@@ -1,2 +1,2 @@
 Annotation paragraph text Chapter 1 Chapter 1 paragraph text Chapter 2
-Chapter 2 paragraph text
+Chapter 2 paragraph text Chapter 2.1 Chapter 2.1 paragraph text
diff --git a/lib/repubmark/elems/chapter.rb b/lib/repubmark/elems/chapter.rb
index e13b72c..31766cf 100644
--- a/lib/repubmark/elems/chapter.rb
+++ b/lib/repubmark/elems/chapter.rb
@@ -54,12 +54,27 @@ module Repubmark
 
       def chapters
         {
-          slug: @slug,
+          slug: anchor,
           title: @title,
           chapters: @chapters.map(&:chapters).freeze,
         }.freeze
       end
 
+      ##################
+      # Helper methods #
+      ##################
+
+      def anchor
+        if parent.instance_of?(self.class) && @level > 2
+          "#{parent.anchor}-#@slug"
+        elsif (anchor_prefix =
+               String(config[:chapter_anchor_prefix]).strip).empty?
+          @slug
+        else
+          "#{anchor_prefix}-#@slug"
+        end.freeze
+      end
+
       ###################
       # Builder methods #
       ###################
@@ -118,9 +133,7 @@ module Repubmark
       end
 
       def build_title_html
-        anchor_prefix = String(config[:chapter_anchor_prefix]).strip
-        anchor = %( id="#{anchor_prefix}-#@slug") unless anchor_prefix.empty?
-        "<h#@level#{anchor}>#@title</h#@level>\n" if @level != 1
+        %(<h#@level id="#{anchor}">#@title</h#@level>\n) if @level != 1
       end
 
       def build_title_gemtext