diff --git a/lib/faraday/connection.rb b/lib/faraday/connection.rb
index ab4075f1..db348557 100644
--- a/lib/faraday/connection.rb
+++ b/lib/faraday/connection.rb
@@ -33,7 +33,8 @@ module Faraday
       @parallel_manager = options[:parallel]
 
       self.url_prefix = url if url
-      proxy(options[:proxy])
+
+      proxy(options.fetch(:proxy) { ENV['http_proxy'] })
 
       @params.update options[:params]   if options[:params]
       @headers.update options[:headers] if options[:headers]
diff --git a/test/connection_test.rb b/test/connection_test.rb
index 3d3e5ce2..474314a0 100644
--- a/test/connection_test.rb
+++ b/test/connection_test.rb
@@ -1,6 +1,17 @@
 require File.expand_path(File.join(File.dirname(__FILE__), 'helper'))
 
 class TestConnection < Faraday::TestCase
+
+  def with_proxy_env(proxy)
+    old_proxy = ENV['http_proxy']
+    ENV['http_proxy'] = proxy
+    begin
+      yield
+    ensure
+      ENV['http_proxy'] = old_proxy
+    end
+  end
+
   def test_initialize_parses_host_out_of_given_url
     conn = Faraday::Connection.new "http://sushi.com"
     assert_equal 'sushi.com', conn.host
@@ -202,31 +213,46 @@ class TestConnection < Faraday::TestCase
   end
 
   def test_proxy_accepts_string
-    conn = Faraday::Connection.new
-    conn.proxy 'http://proxy.com'
-    assert_equal 'proxy.com', conn.proxy[:uri].host
-    assert_equal [:uri],      conn.proxy.keys
+    with_proxy_env "http://duncan.proxy.com:80" do
+      conn = Faraday::Connection.new
+      conn.proxy 'http://proxy.com'
+      assert_equal 'proxy.com', conn.proxy[:uri].host
+      assert_equal [:uri],      conn.proxy.keys
+    end
   end
 
   def test_proxy_accepts_uri
-    conn = Faraday::Connection.new
-    conn.proxy Addressable::URI.parse('http://proxy.com')
-    assert_equal 'proxy.com', conn.proxy[:uri].host
-    assert_equal [:uri],      conn.proxy.keys
+    with_proxy_env "http://duncan.proxy.com:80" do
+      conn = Faraday::Connection.new
+      conn.proxy Addressable::URI.parse('http://proxy.com')
+      assert_equal 'proxy.com', conn.proxy[:uri].host
+      assert_equal [:uri],      conn.proxy.keys
+    end
   end
 
   def test_proxy_accepts_hash_with_string_uri
-    conn = Faraday::Connection.new
-    conn.proxy :uri => 'http://proxy.com', :user => 'rick'
-    assert_equal 'proxy.com', conn.proxy[:uri].host
-    assert_equal 'rick',      conn.proxy[:user]
+    with_proxy_env "http://duncan.proxy.com:80" do
+      conn = Faraday::Connection.new
+      conn.proxy :uri => 'http://proxy.com', :user => 'rick'
+      assert_equal 'proxy.com', conn.proxy[:uri].host
+      assert_equal 'rick',      conn.proxy[:user]
+    end
   end
 
   def test_proxy_accepts_hash
-    conn = Faraday::Connection.new
-    conn.proxy :uri => Addressable::URI.parse('http://proxy.com'), :user => 'rick'
-    assert_equal 'proxy.com', conn.proxy[:uri].host
-    assert_equal 'rick',      conn.proxy[:user]
+    with_proxy_env "http://duncan.proxy.com:80" do
+      conn = Faraday::Connection.new
+      conn.proxy :uri => Addressable::URI.parse('http://proxy.com'), :user => 'rick'
+      assert_equal 'proxy.com', conn.proxy[:uri].host
+      assert_equal 'rick',      conn.proxy[:user]
+    end
+  end
+
+  def test_proxy_accepts_http_env
+    with_proxy_env "http://duncan.proxy.com:80" do
+      conn = Faraday::Connection.new
+      assert_equal 'duncan.proxy.com', conn.proxy[:uri].host
+    end
   end
 
   def test_proxy_requires_uri