diff --git a/gemfiles/rails_5.gemfile.lock b/gemfiles/rails_5.gemfile.lock
index d923ae0..769ab56 100644
--- a/gemfiles/rails_5.gemfile.lock
+++ b/gemfiles/rails_5.gemfile.lock
@@ -3,7 +3,7 @@ PATH
   specs:
     maildown (3.1.0)
       actionmailer (>= 4.0.0)
-      kramdown
+      kramdown-parser-gfm
 
 GEM
   remote: https://rubygems.org/
@@ -58,10 +58,16 @@ GEM
       activesupport (>= 4.2.0)
     i18n (1.6.0)
       concurrent-ruby (~> 1.0)
-    kramdown (2.1.0)
+    kramdown (2.2.1)
+      rexml
+    kramdown-parser-gfm (1.1.0)
+      kramdown (~> 2.0)
     loofah (2.2.3)
       crass (~> 1.0.2)
       nokogiri (>= 1.5.9)
+    m (1.5.1)
+      method_source (>= 0.6.7)
+      rake (>= 0.9.2.2)
     mail (2.7.1)
       mini_mime (>= 0.1.1)
     method_source (0.9.2)
@@ -98,6 +104,7 @@ GEM
       rake (>= 0.8.7)
       thor (>= 0.18.1, < 2.0)
     rake (12.3.2)
+    rexml (3.2.4)
     sprockets (3.7.2)
       concurrent-ruby (~> 1.0)
       rack (> 1, < 3)
@@ -119,6 +126,7 @@ PLATFORMS
 
 DEPENDENCIES
   appraisal
+  m
   maildown!
   rails (= 5.0.7.2)
   railties
@@ -126,4 +134,4 @@ DEPENDENCIES
   sqlite3 (~> 1.3.6)
 
 BUNDLED WITH
-   2.0.2
+   2.1.4
diff --git a/gemfiles/rails_51.gemfile.lock b/gemfiles/rails_51.gemfile.lock
index 20a4950..cdab2d4 100644
--- a/gemfiles/rails_51.gemfile.lock
+++ b/gemfiles/rails_51.gemfile.lock
@@ -3,7 +3,7 @@ PATH
   specs:
     maildown (3.1.0)
       actionmailer (>= 4.0.0)
-      kramdown
+      kramdown-parser-gfm
 
 GEM
   remote: https://rubygems.org/
@@ -58,10 +58,16 @@ GEM
       activesupport (>= 4.2.0)
     i18n (1.6.0)
       concurrent-ruby (~> 1.0)
-    kramdown (2.1.0)
+    kramdown (2.2.1)
+      rexml
+    kramdown-parser-gfm (1.1.0)
+      kramdown (~> 2.0)
     loofah (2.2.3)
       crass (~> 1.0.2)
       nokogiri (>= 1.5.9)
+    m (1.5.1)
+      method_source (>= 0.6.7)
+      rake (>= 0.9.2.2)
     mail (2.7.1)
       mini_mime (>= 0.1.1)
     method_source (0.9.2)
@@ -98,6 +104,7 @@ GEM
       rake (>= 0.8.7)
       thor (>= 0.18.1, < 2.0)
     rake (12.3.2)
+    rexml (3.2.4)
     sprockets (3.7.2)
       concurrent-ruby (~> 1.0)
       rack (> 1, < 3)
@@ -119,6 +126,7 @@ PLATFORMS
 
 DEPENDENCIES
   appraisal
+  m
   maildown!
   rails (= 5.1.7)
   railties
@@ -126,4 +134,4 @@ DEPENDENCIES
   sqlite3 (~> 1.3.6)
 
 BUNDLED WITH
-   2.0.2
+   2.1.4
diff --git a/gemfiles/rails_52.gemfile.lock b/gemfiles/rails_52.gemfile.lock
index faa7fe2..fe4653a 100644
--- a/gemfiles/rails_52.gemfile.lock
+++ b/gemfiles/rails_52.gemfile.lock
@@ -3,7 +3,7 @@ PATH
   specs:
     maildown (3.1.0)
       actionmailer (>= 4.0.0)
-      kramdown
+      kramdown-parser-gfm
 
 GEM
   remote: https://rubygems.org/
@@ -62,10 +62,16 @@ GEM
       activesupport (>= 4.2.0)
     i18n (1.6.0)
       concurrent-ruby (~> 1.0)
-    kramdown (2.1.0)
+    kramdown (2.2.1)
+      rexml
+    kramdown-parser-gfm (1.1.0)
+      kramdown (~> 2.0)
     loofah (2.2.3)
       crass (~> 1.0.2)
       nokogiri (>= 1.5.9)
+    m (1.5.1)
+      method_source (>= 0.6.7)
+      rake (>= 0.9.2.2)
     mail (2.7.1)
       mini_mime (>= 0.1.1)
     marcel (0.3.3)
@@ -106,6 +112,7 @@ GEM
       rake (>= 0.8.7)
       thor (>= 0.19.0, < 2.0)
     rake (12.3.2)
+    rexml (3.2.4)
     sprockets (3.7.2)
       concurrent-ruby (~> 1.0)
       rack (> 1, < 3)
@@ -127,6 +134,7 @@ PLATFORMS
 
 DEPENDENCIES
   appraisal
+  m
   maildown!
   rails (= 5.2.3)
   railties
@@ -134,4 +142,4 @@ DEPENDENCIES
   sqlite3 (~> 1.3.6)
 
 BUNDLED WITH
-   2.0.2
+   2.1.4
diff --git a/gemfiles/rails_6.gemfile.lock b/gemfiles/rails_6.gemfile.lock
index 5d29586..7db9a46 100644
--- a/gemfiles/rails_6.gemfile.lock
+++ b/gemfiles/rails_6.gemfile.lock
@@ -3,7 +3,7 @@ PATH
   specs:
     maildown (3.1.0)
       actionmailer (>= 4.0.0)
-      kramdown
+      kramdown-parser-gfm
 
 GEM
   remote: https://rubygems.org/
@@ -75,10 +75,16 @@ GEM
       activesupport (>= 4.2.0)
     i18n (1.6.0)
       concurrent-ruby (~> 1.0)
-    kramdown (2.1.0)
+    kramdown (2.2.1)
+      rexml
+    kramdown-parser-gfm (1.1.0)
+      kramdown (~> 2.0)
     loofah (2.3.0)
       crass (~> 1.0.2)
       nokogiri (>= 1.5.9)
+    m (1.5.1)
+      method_source (>= 0.6.7)
+      rake (>= 0.9.2.2)
     mail (2.7.1)
       mini_mime (>= 0.1.1)
     marcel (0.3.3)
@@ -121,6 +127,7 @@ GEM
       rake (>= 0.8.7)
       thor (>= 0.20.3, < 2.0)
     rake (13.0.0)
+    rexml (3.2.4)
     sprockets (3.7.2)
       concurrent-ruby (~> 1.0)
       rack (> 1, < 3)
@@ -143,6 +150,7 @@ PLATFORMS
 
 DEPENDENCIES
   appraisal
+  m
   maildown!
   rails (= 6.0.0)
   railties
@@ -150,4 +158,4 @@ DEPENDENCIES
   sqlite3 (~> 1.4)
 
 BUNDLED WITH
-   2.0.2
+   2.1.4
diff --git a/gemfiles/rails_head.gemfile.lock b/gemfiles/rails_head.gemfile.lock
index 37b5a8c..d757c98 100644
--- a/gemfiles/rails_head.gemfile.lock
+++ b/gemfiles/rails_head.gemfile.lock
@@ -84,7 +84,7 @@ PATH
   specs:
     maildown (3.1.0)
       actionmailer (>= 4.0.0)
-      kramdown
+      kramdown-parser-gfm
 
 GEM
   remote: https://rubygems.org/
@@ -101,10 +101,16 @@ GEM
       activesupport (>= 4.2.0)
     i18n (1.6.0)
       concurrent-ruby (~> 1.0)
-    kramdown (2.1.0)
+    kramdown (2.2.1)
+      rexml
+    kramdown-parser-gfm (1.1.0)
+      kramdown (~> 2.0)
     loofah (2.2.3)
       crass (~> 1.0.2)
       nokogiri (>= 1.5.9)
+    m (1.5.1)
+      method_source (>= 0.6.7)
+      rake (>= 0.9.2.2)
     mail (2.7.1)
       mini_mime (>= 0.1.1)
     marcel (0.3.3)
@@ -126,6 +132,7 @@ GEM
     rails-html-sanitizer (1.0.4)
       loofah (~> 2.2, >= 2.2.2)
     rake (12.3.2)
+    rexml (3.2.4)
     sprockets (3.7.2)
       concurrent-ruby (~> 1.0)
       rack (> 1, < 3)
@@ -148,6 +155,7 @@ PLATFORMS
 
 DEPENDENCIES
   appraisal
+  m
   maildown!
   rails!
   railties
@@ -155,4 +163,4 @@ DEPENDENCIES
   sqlite3 (~> 1.4)
 
 BUNDLED WITH
-   2.0.2
+   2.1.4
diff --git a/lib/maildown/markdown_engine.rb b/lib/maildown/markdown_engine.rb
index 16e8e74..7cc5354 100644
--- a/lib/maildown/markdown_engine.rb
+++ b/lib/maildown/markdown_engine.rb
@@ -49,7 +49,7 @@ def self.text_block
     end
 
     def self.default_html_block
-      ->(string) { Kramdown::Document.new(string).to_html }
+      ->(string) { Kramdown::Document.new(string, input: "GFM").to_html }
     end
 
     def self.default_text_block
diff --git a/maildown.gemspec b/maildown.gemspec
index ead02ec..38c567b 100644
--- a/maildown.gemspec
+++ b/maildown.gemspec
@@ -18,9 +18,10 @@ Gem::Specification.new do |s|
   s.test_files = Dir["test/**/*"]
 
   s.add_dependency "actionmailer", ">= 4.0.0"
-  s.add_dependency "kramdown"
+  s.add_dependency "kramdown-parser-gfm"
 
   s.add_development_dependency "railties"
+  s.add_development_dependency "m"
   s.add_development_dependency "sqlite3"
   s.add_development_dependency "rake"
 end
diff --git a/test/test_helper.rb b/test/test_helper.rb
index a5e7b4d..fdcad47 100644
--- a/test/test_helper.rb
+++ b/test/test_helper.rb
@@ -3,7 +3,7 @@
 
 require File.expand_path("../dummy/config/environment.rb",  __FILE__)
 require "rails/test_help"
-require "kramdown"
+require "kramdown-parser-gfm"
 
 Rails.backtrace_cleaner.remove_silencers!
 
diff --git a/test/unit/markdown_engine_test.rb b/test/unit/markdown_engine_test.rb
index 0f73c71..6f52d11 100644
--- a/test/unit/markdown_engine_test.rb
+++ b/test/unit/markdown_engine_test.rb
@@ -34,4 +34,11 @@ def teardown
     end
     thread.join
   end
+
+  test "handles code fences (GFM)" do
+    markdown = "```\nbar\n```"
+
+    actual = Maildown::MarkdownEngine.to_html(markdown)
+    assert_equal "<pre><code>bar\n</code></pre>\n", actual
+  end
 end