diff --git a/Gemfile b/Gemfile
index b25d8dd..912c76e 100644
--- a/Gemfile
+++ b/Gemfile
@@ -17,7 +17,8 @@ gem 'words_counted', git: 'https://github.com/werthen/words_counted'
 
 group :development do
   gem 'adsf'
-  gem 'thin'
+  # puma instead of thin, see https://github.com/nanoc/nanoc/issues/1499
+  gem 'puma'
   gem 'highline'
   gem 'terminal-notifier'
   gem 'terminal-notifier-guard'
diff --git a/Gemfile.lock b/Gemfile.lock
index 048d8b7..d1d54ff 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -18,14 +18,12 @@ GEM
     colored (1.2)
     concurrent-ruby (1.1.8)
     cri (2.15.11)
-    daemons (1.3.1)
     ddmemoize (1.0.0)
       ddmetrics (~> 1.0)
       ref (~> 2.0)
     ddmetrics (1.0.1)
     ddplugin (1.0.3)
     diff-lcs (1.4.4)
-    eventmachine (1.2.7)
     execjs (2.7.0)
     ffi (1.14.2)
     formatador (0.2.5)
@@ -98,6 +96,7 @@ GEM
       nanoc-cli (~> 4.11, >= 4.11.15)
       nanoc-core (~> 4.11, >= 4.11.15)
     nenv (0.3.0)
+    nio4r (2.5.5)
     nokogiri (1.11.1)
       mini_portile2 (~> 2.5.0)
       racc (~> 1.4)
@@ -112,6 +111,8 @@ GEM
       coderay (~> 1.1)
       method_source (~> 1.0)
     public_suffix (4.0.6)
+    puma (5.2.1)
+      nio4r (~> 2.0)
     racc (1.5.2)
     rack (2.2.3)
     rainpress (1.0.1)
@@ -127,10 +128,6 @@ GEM
     slow_enumerator_tools (1.1.0)
     terminal-notifier (2.0.0)
     terminal-notifier-guard (1.7.0)
-    thin (1.8.0)
-      daemons (~> 1.0, >= 1.0.9)
-      eventmachine (~> 1.0, >= 1.0.4)
-      rack (>= 1, < 3)
     thor (1.1.0)
     tomlrb (1.3.0)
     tty-color (0.6.0)
@@ -164,11 +161,11 @@ DEPENDENCIES
   mini_racer
   nanoc
   pandoc-ruby
+  puma
   rainpress
   sassc
   terminal-notifier
   terminal-notifier-guard
-  thin
   typogruby
   uglifier (>= 4.0.0)
   w3c_validators