diff --git a/lib/omniauth/failure_endpoint.rb b/lib/omniauth/failure_endpoint.rb
index 9b6b866..d9edbcc 100644
--- a/lib/omniauth/failure_endpoint.rb
+++ b/lib/omniauth/failure_endpoint.rb
@@ -17,7 +17,7 @@ module OmniAuth
     end
 
     def call
-      raise_out! if OmniAuth.config.failure_raise_out_environments.include?(ENV['RACK_ENV'])
+      raise_out! if OmniAuth.config.failure_raise_out_environments.include?(ENV['RACK_ENV'].to_s)
       redirect_to_failure
     end
 
diff --git a/spec/helper.rb b/spec/helper.rb
index c2d530a..7b02da4 100644
--- a/spec/helper.rb
+++ b/spec/helper.rb
@@ -13,7 +13,6 @@ require 'omniauth'
 require 'omniauth/test'
 
 OmniAuth.config.logger = Logger.new("/dev/null")
-ENV['RACK_ENV'] ||= 'test'
 
 RSpec.configure do |config|
   config.include Rack::Test::Methods
diff --git a/spec/omniauth/failure_endpoint_spec.rb b/spec/omniauth/failure_endpoint_spec.rb
index 45ff18f..e4f5cf4 100644
--- a/spec/omniauth/failure_endpoint_spec.rb
+++ b/spec/omniauth/failure_endpoint_spec.rb
@@ -5,6 +5,9 @@ describe OmniAuth::FailureEndpoint do
 
   context "raise-out environment" do
     before do
+      @rack_env = ENV['RACK_ENV']
+      ENV['RACK_ENV'] = 'test'
+
       @default = OmniAuth.config.failure_raise_out_environments
       OmniAuth.config.failure_raise_out_environments = ['test']
     end
@@ -20,6 +23,7 @@ describe OmniAuth::FailureEndpoint do
     end
 
     after do
+      ENV['RACK_ENV'] = @rack_env
       OmniAuth.config.failure_raise_out_environments = @default
     end
   end