diff --git a/lib/warbler/web_server.rb b/lib/warbler/web_server.rb
index 5dce7078..d2ac03fa 100644
--- a/lib/warbler/web_server.rb
+++ b/lib/warbler/web_server.rb
@@ -20,7 +20,7 @@ def local_path
           FileUtils.mkdir_p File.dirname(cached_path) #:nocov:
           require 'open-uri'                    #:nocov:
           begin
-            open(download_url) do |stream|        #:nocov:
+            URI.open(download_url) do |stream|        #:nocov:
               File.open(cached_path, "wb") do |f| #:nocov:
                 while buf = stream.read(4096) #:nocov:
                   f << buf                    #:nocov:
diff --git a/spec/warbler/web_server_spec.rb b/spec/warbler/web_server_spec.rb
index 8da8c1eb..7cfcd3b4 100644
--- a/spec/warbler/web_server_spec.rb
+++ b/spec/warbler/web_server_spec.rb
@@ -8,9 +8,9 @@ def self.reset_local_repository
 
 describe Warbler::WebServer::Artifact do
 
-  @@_env = ENV.to_h
-
-  after(:all) { ENV.clear; ENV.update @@_env }
+  before(:all) do
+    @_env = ENV.to_h
+  end
 
   before do
     Warbler::WebServer::Artifact.reset_local_repository
@@ -18,6 +18,8 @@ def self.reset_local_repository
 
   after(:all) do
     Warbler::WebServer::Artifact.reset_local_repository
+    ENV.clear
+    ENV.update @_env
   end
 
   let(:sample_artifact) do