diff --git a/Gemfile b/Gemfile
index 406fe34eb..ff8ad4de9 100644
--- a/Gemfile
+++ b/Gemfile
@@ -24,7 +24,7 @@ end
 group :test do
   gem 'grape-entity', '~> 0.6'
   gem 'maruku'
-  gem 'rack-test'
+  gem 'rack-test', '~> 0.6.3'
   gem 'rspec', '~> 3.0'
   gem 'cookiejar'
   gem 'rack-jsonp', require: 'rack/jsonp'
diff --git a/gemfiles/multi_json.gemfile b/gemfiles/multi_json.gemfile
index dc2a874e1..d2abcdff8 100644
--- a/gemfiles/multi_json.gemfile
+++ b/gemfiles/multi_json.gemfile
@@ -24,7 +24,7 @@ end
 group :test do
   gem 'grape-entity', '~> 0.6'
   gem 'maruku'
-  gem 'rack-test'
+  gem 'rack-test', '~> 0.6.3'
   gem 'rspec', '~> 3.0'
   gem 'cookiejar'
   gem 'rack-jsonp', require: 'rack/jsonp'
diff --git a/gemfiles/multi_xml.gemfile b/gemfiles/multi_xml.gemfile
index af3b7eedf..69d112458 100644
--- a/gemfiles/multi_xml.gemfile
+++ b/gemfiles/multi_xml.gemfile
@@ -24,7 +24,7 @@ end
 group :test do
   gem 'grape-entity', '~> 0.6'
   gem 'maruku'
-  gem 'rack-test'
+  gem 'rack-test', '~> 0.6.3'
   gem 'rspec', '~> 3.0'
   gem 'cookiejar'
   gem 'rack-jsonp', require: 'rack/jsonp'
diff --git a/gemfiles/rack_1.5.2.gemfile b/gemfiles/rack_1.5.2.gemfile
index ae9e8174d..fb4036075 100644
--- a/gemfiles/rack_1.5.2.gemfile
+++ b/gemfiles/rack_1.5.2.gemfile
@@ -24,7 +24,7 @@ end
 group :test do
   gem 'grape-entity', '~> 0.6'
   gem 'maruku'
-  gem 'rack-test'
+  gem 'rack-test', '~> 0.6.3'
   gem 'rspec', '~> 3.0'
   gem 'cookiejar'
   gem 'rack-jsonp', require: 'rack/jsonp'
diff --git a/gemfiles/rack_edge.gemfile b/gemfiles/rack_edge.gemfile
index 589bf59c4..fa76907fb 100644
--- a/gemfiles/rack_edge.gemfile
+++ b/gemfiles/rack_edge.gemfile
@@ -24,7 +24,7 @@ end
 group :test do
   gem 'grape-entity', '~> 0.6'
   gem 'maruku'
-  gem 'rack-test'
+  gem 'rack-test', '~> 0.6.3'
   gem 'rspec', '~> 3.0'
   gem 'cookiejar'
   gem 'rack-jsonp', require: 'rack/jsonp'
diff --git a/gemfiles/rails_3.gemfile b/gemfiles/rails_3.gemfile
index 29f753f49..fb43932b8 100644
--- a/gemfiles/rails_3.gemfile
+++ b/gemfiles/rails_3.gemfile
@@ -25,7 +25,7 @@ end
 group :test do
   gem 'grape-entity', '~> 0.6'
   gem 'maruku'
-  gem 'rack-test'
+  gem 'rack-test', '~> 0.6.3'
   gem 'rspec', '~> 3.0'
   gem 'cookiejar'
   gem 'rack-jsonp', require: 'rack/jsonp'
diff --git a/gemfiles/rails_4.gemfile b/gemfiles/rails_4.gemfile
index e3cab9468..c3a6eeead 100644
--- a/gemfiles/rails_4.gemfile
+++ b/gemfiles/rails_4.gemfile
@@ -24,7 +24,7 @@ end
 group :test do
   gem 'grape-entity', '~> 0.6'
   gem 'maruku'
-  gem 'rack-test'
+  gem 'rack-test', '~> 0.6.3'
   gem 'rspec', '~> 3.0'
   gem 'cookiejar'
   gem 'rack-jsonp', require: 'rack/jsonp'
diff --git a/gemfiles/rails_5.gemfile b/gemfiles/rails_5.gemfile
index e00ea9224..7f6bfc0bf 100644
--- a/gemfiles/rails_5.gemfile
+++ b/gemfiles/rails_5.gemfile
@@ -24,7 +24,7 @@ end
 group :test do
   gem 'grape-entity', '~> 0.6'
   gem 'maruku'
-  gem 'rack-test'
+  gem 'rack-test', '~> 0.6.3'
   gem 'rspec', '~> 3.0'
   gem 'cookiejar'
   gem 'rack-jsonp', require: 'rack/jsonp'
diff --git a/gemfiles/rails_edge.gemfile b/gemfiles/rails_edge.gemfile
index 972f7fdee..f693f8521 100644
--- a/gemfiles/rails_edge.gemfile
+++ b/gemfiles/rails_edge.gemfile
@@ -24,7 +24,7 @@ end
 group :test do
   gem 'grape-entity', '~> 0.6'
   gem 'maruku'
-  gem 'rack-test'
+  gem 'rack-test', '~> 0.6.3'
   gem 'rspec', '~> 3.0'
   gem 'cookiejar'
   gem 'rack-jsonp', require: 'rack/jsonp'