diff --git a/Gemfile b/Gemfile
index 3a61d83..bd0ef75 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,3 +1,5 @@
+require 'rbconfig'
+
 source 'https://rubygems.org'
 
 gem 'rake'
@@ -15,3 +17,7 @@ gem 'systemu'
 gem 'listen'
 gem 'guard-nanoc'
 gem 'adsf'
+
+if RbConfig::CONFIG['target_os'] =~ /(?i-mx:bsd|dragonfly)/
+  gem 'rb-kqueue', '>= 0.2'
+end
diff --git a/Gemfile.lock b/Gemfile.lock
index 7a2b850..ef05a74 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -70,6 +70,8 @@ GEM
     rb-fsevent (0.10.2)
     rb-inotify (0.9.10)
       ffi (>= 0.5.0, < 2)
+    rb-kqueue (0.2.5)
+      ffi (>= 0.5.0)
     rdiscount (2.2.0.1)
     ruby_dep (1.5.0)
     rubypants (0.6.0)
@@ -99,10 +101,11 @@ DEPENDENCIES
   nanoc (~> 3.0)
   nokogiri
   rake
+  rb-kqueue (>= 0.2)
   rdiscount
   rubypants
   sass
   systemu
 
 BUNDLED WITH
-   1.15.4
+   1.16.0