diff --git a/Gemfile.lock b/Gemfile.lock
index cf2af84..ed4dfff 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -9,7 +9,7 @@ PATH
       http (= 0.5.0)
       mime-types (~> 2.4.0)
       nio4r (~> 1.1.0)
-      rack (~> 1.5.0)
+      rack (>= 1.5, < 2.3)
       reel (= 0.4.0)
       reel-rack (= 0.1.0)
       ruby-progressbar
@@ -70,7 +70,7 @@ GEM
       http_parser.rb
     http-cookie (1.0.2)
       domain_name (~> 0.5)
-    http_parser.rb (0.6.0)
+    http_parser.rb (0.8.0)
     json (1.8.3)
     listen (3.0.1)
       rb-fsevent (>= 0.9.3)
@@ -95,7 +95,7 @@ GEM
       coderay (~> 1.1.0)
       method_source (~> 0.8.1)
       slop (~> 3.4)
-    rack (1.5.5)
+    rack (2.1.4.1)
     rake (10.4.2)
     rb-fsevent (0.9.5)
     rb-inotify (0.9.5)
@@ -126,7 +126,7 @@ GEM
       diff-lcs (>= 1.2.0, < 2.0)
       rspec-support (~> 3.3.0)
     rspec-support (3.3.0)
-    ruby-progressbar (1.7.5)
+    ruby-progressbar (1.11.0)
     shellany (0.0.1)
     simplecov (0.10.0)
       docile (~> 1.1.0)
diff --git a/airplayer.gemspec b/airplayer.gemspec
index 4615c67..3394936 100644
--- a/airplayer.gemspec
+++ b/airplayer.gemspec
@@ -27,7 +27,7 @@ Gem::Specification.new do |spec|
   spec.add_runtime_dependency 'mime-types', '~> 2.4.0'
 
   spec.add_runtime_dependency 'airplay', '~> 1.0.2'
-  spec.add_runtime_dependency 'rack', '~> 1.5.0'
+  spec.add_runtime_dependency 'rack', '>= 1.5', '< 2.3'
   spec.add_runtime_dependency 'http', '= 0.5.0'
   spec.add_runtime_dependency 'nio4r', '~> 1.1.0'
   spec.add_runtime_dependency 'reel', '= 0.4.0'