diff --git a/lib/travis/web/app/alt_versions.rb b/lib/travis/web/app/alt_versions.rb
index 8d17fdc2..7a3671c7 100644
--- a/lib/travis/web/app/alt_versions.rb
+++ b/lib/travis/web/app/alt_versions.rb
@@ -7,7 +7,7 @@ class Travis::Web::App::AltVersions
 
   def call(env)
     alt = alt_from_params(env) || alt_from_cookie(env)
-    env['travis.alt'] = alt if alt
+    env['travis.alt'] = alt if alt && alt != 'default'
     status, headers, body = app.call(env)
     headers['Set-Cookie'] = cookie(alt) if alt
     [status, headers, body]
@@ -16,14 +16,14 @@ class Travis::Web::App::AltVersions
   private
 
     def cookie(alt)
-      "alt=#{alt}; path=/; max-age=#{alt == 'default' ? 0 : 86400}"
+      "alt=#{alt == 'default' ? '' : alt}; path=/; max-age=#{alt == 'default' ? 0 : 86400}"
     end
 
     def alt_from_params(env)
-      $1 if env['QUERY_STRING'] =~ /alt=([^&]*)/
+      $1 if env['QUERY_STRING'] =~ /alt=([^&]+)/
     end
 
     def alt_from_cookie(env)
-      $1 if env['HTTP_COOKIE'] =~ /alt=([^;]*)/
+      $1 if env['HTTP_COOKIE'] =~ /alt=([^;]+)/
     end
 end
diff --git a/spec/app_spec.rb b/spec/app_spec.rb
index 919578da..535367fb 100644
--- a/spec/app_spec.rb
+++ b/spec/app_spec.rb
@@ -47,7 +47,8 @@ describe Travis::Web::App do
 
     context 'passing default as an alt param' do
       before  { get('/?alt=default') }
-      example { headers['Set-Cookie'].should == 'alt=default; path=/; max-age=0' }
+      example { last_response.body.should_not =~ /\/assets\/[^\/]+\/scripts\/app.js/ }
+      example { headers['Set-Cookie'].should == 'alt=; path=/; max-age=0' }
     end
   end
 end