diff --git a/rack-livereload.gemspec b/rack-livereload.gemspec
index be758d4..0c14dc1 100644
--- a/rack-livereload.gemspec
+++ b/rack-livereload.gemspec
@@ -32,7 +32,7 @@ Gem::Specification.new do |s|
   s.add_development_dependency "guard-cucumber"
   s.add_development_dependency "guard-livereload"
   s.add_development_dependency "webmock"
-  s.add_development_dependency "nokogiri"
+  s.add_development_dependency "nokogiri", ("< 1.6" if RUBY_VERSION < "1.9") # Nokogiri >= 1.6 requires Ruby >= 1.9
   s.add_development_dependency 'appraisal', '~> 0.4'
   s.add_runtime_dependency "rack"
 end