diff --git a/.rubocop_todo.yml b/.rubocop_todo.yml
index f9b7fdd11..1ffc73e93 100644
--- a/.rubocop_todo.yml
+++ b/.rubocop_todo.yml
@@ -14,7 +14,7 @@ Metrics/AbcSize:
 # Offense count: 5
 # Configuration parameters: CountComments, CountAsOne.
 Metrics/ClassLength:
-  Max: 256
+  Max: 260
 
 # Offense count: 15
 # Configuration parameters: IgnoredMethods.
diff --git a/Gemfile b/Gemfile
index 66c9d29f4..fcbe1d39a 100644
--- a/Gemfile
+++ b/Gemfile
@@ -7,6 +7,7 @@ ruby RUBY_VERSION
 gem 'jruby-openssl', '~> 0.10.7', platforms: :jruby
 
 group :development, :test do
+  gem 'irb'
   gem 'pry'
   gem 'rake'
 end
diff --git a/lib/faraday/connection.rb b/lib/faraday/connection.rb
index 6344f6a0c..7a9849ad1 100644
--- a/lib/faraday/connection.rb
+++ b/lib/faraday/connection.rb
@@ -433,13 +433,18 @@ def url_prefix=(url, encoder = nil)
       uri.query = nil
 
       with_uri_credentials(uri) do |user, password|
-        basic_auth user, password
+        set_basic_auth(user, password)
         uri.user = uri.password = nil
       end
 
       @proxy = proxy_from_env(url) unless @manual_proxy
     end
 
+    def set_basic_auth(user, password)
+      header = Faraday::Request::BasicAuthentication.header(user, password)
+      headers[Faraday::Request::Authorization::KEY] = header
+    end
+
     # Sets the path prefix and ensures that it always has a leading
     # slash.
     #