diff --git a/lib/travis/api/v3/queries/repositories.rb b/lib/travis/api/v3/queries/repositories.rb
index 3994c384..56593383 100644
--- a/lib/travis/api/v3/queries/repositories.rb
+++ b/lib/travis/api/v3/queries/repositories.rb
@@ -3,7 +3,15 @@ module Travis::API::V3
     params :active, :private, :starred, prefix: :repository
     sortable_by :id, :github_id, :owner_name, :name, active: sort_condition(:active),
                 :'default_branch.last_build' => 'builds.started_at',
-                :current_build_id => "repositories.current_build_id %{order} NULLS LAST"
+                :current_build => "repositories.current_build_id %{order} NULLS LAST"
+
+    # this is a hack for a bug in AR that generates invalid query when it tries
+    # to include `current_build` and join it at the same time. We don't actually
+    # need the join, but it will be automatically added, because `current_build`
+    # is an association. This prevents adding the join. We will probably be able
+    # to remove it once we move to newer AR versions
+    prevent_sortable_join :current_build
+    experimental_sortable_by :current_build
 
     def for_member(user, **options)
       all(user: user, **options).joins(:users).where(users: user_condition(user), invalidated_at: nil)
@@ -37,7 +45,7 @@ module Travis::API::V3
       end
 
       list = list.includes(default_branch: :last_build)
-      list = list.includes(:current_build)
+      list = list.includes(:current_build) if includes? 'repository.current_build'.freeze
       list = list.includes(default_branch: { last_build: :commit }) if includes? 'build.commit'.freeze
       sort list
     end
diff --git a/lib/travis/api/v3/query.rb b/lib/travis/api/v3/query.rb
index af4e5006..b9d47fe7 100644
--- a/lib/travis/api/v3/query.rb
+++ b/lib/travis/api/v3/query.rb
@@ -70,6 +70,26 @@ module Travis::API::V3
       mapping.each { |key, value| sort_by[key.to_s]   = prefix(value) }
     end
 
+    def self.prevent_sortable_join(*fields)
+      dont_join.push(*fields.map(&:to_s))
+    end
+
+    @dont_join = []
+    def self.dont_join
+      @dont_join ||= superclass.dont_join.dup
+    end
+
+    @experimental_sortable_by = []
+    def self.experimental_sortable_by(*fields)
+      @experimental_sortable_by ||= []
+
+      if fields.first
+        @experimental_sortable_by.push(*fields.map(&:to_s))
+      end
+
+      @experimental_sortable_by
+    end
+
     def self.sort_condition(condition)
       if condition.is_a? Hash
         condition = condition.map { |e| e.map { |v| prefix(v) }.join(" = ".freeze) }.join(" and ".freeze)
@@ -172,6 +192,7 @@ module Travis::API::V3
     end
 
     def sort_join?(collection, field)
+      return if self.class.dont_join.include?(field)
       !collection.reflect_on_association(field.to_sym).nil?
     end
 
diff --git a/lib/travis/api/v3/renderer/model_renderer.rb b/lib/travis/api/v3/renderer/model_renderer.rb
index 0b3a0c5e..dd5bdc0b 100644
--- a/lib/travis/api/v3/renderer/model_renderer.rb
+++ b/lib/travis/api/v3/renderer/model_renderer.rb
@@ -26,6 +26,17 @@ module Travis::API::V3
       @representations ||= superclass.representations.dup
     end
 
+    @experimental_representations = []
+    def self.experimental_representations(*representations)
+      @experimental_representations ||= superclass.experimental_representations.dup
+
+      if representations.first
+        @experimental_representations.push(*representations)
+      end
+
+      @experimental_representations
+    end
+
     @available_attributes = Set.new
     def self.available_attributes
       @available_attributes ||= superclass.available_attributes.dup
diff --git a/lib/travis/api/v3/renderer/repository.rb b/lib/travis/api/v3/renderer/repository.rb
index c1c3bf30..546b4c6e 100644
--- a/lib/travis/api/v3/renderer/repository.rb
+++ b/lib/travis/api/v3/renderer/repository.rb
@@ -3,7 +3,10 @@ require 'travis/api/v3/renderer/model_renderer'
 module Travis::API::V3
   class Renderer::Repository < Renderer::ModelRenderer
     representation(:minimal,  :id, :name, :slug)
-    representation(:standard, :id, :name, :slug, :description, :github_language, :active, :private, :owner, :default_branch, :starred, :current_build)
+    representation(:standard, :id, :name, :slug, :description, :github_language, :active, :private, :owner, :default_branch, :starred)
+    representation(:experimental, :id, :name, :slug, :description, :github_language, :active, :private, :owner, :default_branch, :starred, :current_build)
+
+    experimental_representations(:experimental)
 
     def active
       !!model.active
diff --git a/lib/travis/api/v3/service_index.rb b/lib/travis/api/v3/service_index.rb
index 0d17b0ea..ee3ebd04 100644
--- a/lib/travis/api/v3/service_index.rb
+++ b/lib/travis/api/v3/service_index.rb
@@ -85,9 +85,17 @@ module Travis::API::V3
         data = resources[resource.identifier] ||= { :@type => :resource, :actions => {} }
         data.merge! resource.meta_data
 
-        if renderer              = Renderer[resource.identifier, false]
-          data[:attributes]      = renderer.available_attributes if renderer.respond_to? :available_attributes
-          data[:representations] = renderer.representations      if renderer.respond_to? :representations
+        if renderer = Renderer[resource.identifier, false]
+
+          data[:attributes] = renderer.available_attributes if renderer.respond_to? :available_attributes
+
+          if renderer.respond_to? :representations
+            representations = renderer.representations
+            if renderer.respond_to? :experimental_representations
+              representations = representations.reject { |k| renderer.experimental_representations.include? k }
+            end
+            data[:representations] = representations
+          end
         end
 
         if permissions           = Permissions[resource.identifier, false]
@@ -102,7 +110,7 @@ module Travis::API::V3
           if factory.params and factory.params.include? "sort_by".freeze
             query = Queries[resource.identifier]
             if query and query.sortable?
-              resources[resource.identifier][:sortable_by]  = query.sort_by.keys
+              resources[resource.identifier][:sortable_by]  = query.sort_by.keys - query.experimental_sortable_by
               resources[resource.identifier][:default_sort] = query.default_sort unless query.default_sort.empty?
             end
           end
diff --git a/spec/v3/services/owner/find_spec.rb b/spec/v3/services/owner/find_spec.rb
index ddab6ccf..5bb8e591 100644
--- a/spec/v3/services/owner/find_spec.rb
+++ b/spec/v3/services/owner/find_spec.rb
@@ -79,8 +79,7 @@ describe Travis::API::V3::Services::Owner::Find, set_app: true do
             "@href"           => "/v3/repo/#{repo.id}/branch/master",
             "@representation" => "minimal",
             "name"            => "master"},
-          "starred"           => false,
-          "current_build"     => nil
+          "starred"           => false
         }]
       }}
     end
@@ -128,8 +127,7 @@ describe Travis::API::V3::Services::Owner::Find, set_app: true do
             "@href"         => "/v3/repo/#{repo.id}/branch/master",
             "@representation"=> "minimal",
             "name"          => "master"},
-          "starred"         => false,
-          "current_build"   => nil
+          "starred"         => false
         }]
       }}
     end
diff --git a/spec/v3/services/repositories/for_current_user_spec.rb b/spec/v3/services/repositories/for_current_user_spec.rb
index f724bbb7..0d86a6d2 100644
--- a/spec/v3/services/repositories/for_current_user_spec.rb
+++ b/spec/v3/services/repositories/for_current_user_spec.rb
@@ -2,7 +2,6 @@ describe Travis::API::V3::Services::Repositories::ForCurrentUser, set_app: true
   let(:repo)  { Travis::API::V3::Models::Repository.where(owner_name: 'svenfuchs', name: 'minimal').first }
   let(:build) { repo.builds.first }
   let(:jobs)  { Travis::API::V3::Models::Build.find(build.id).jobs }
-  let(:current_build) { repo.builds.first }
 
   let(:token)   { Travis::Api::App::AccessToken.create(user: repo.owner, app_id: 1)             }
   let(:headers) {{ 'HTTP_AUTHORIZATION' => "token #{token}"                                    }}
@@ -11,7 +10,6 @@ describe Travis::API::V3::Services::Repositories::ForCurrentUser, set_app: true
   after         { repo.update_attribute(:private, false)                                        }
 
   describe "private repository, private API, authenticated as user with access" do
-    before  { repo.update_attribute(:current_build_id, current_build.id) }
     before  { get("/v3/repos", {}, headers)    }
     example { expect(last_response).to be_ok   }
     example { expect(JSON.load(body)).to be == {
@@ -64,18 +62,6 @@ describe Travis::API::V3::Services::Repositories::ForCurrentUser, set_app: true
           "@representation"  => "minimal",
           "name"             => "master"},
         "starred"            => false,
-        "current_build"      => {
-          "@type"            => "build",
-          "@href"            => "/v3/build/#{current_build.id}",
-          "@representation"  => "minimal",
-          "id"               => current_build.id.to_i,
-          "number"           => current_build.number,
-          "state"            => current_build.state,
-          "duration"         => current_build.duration,
-          "event_type"       => current_build.event_type,
-          "previous_state"   => current_build.previous_state,
-          "started_at"       => current_build.started_at.strftime("%Y-%m-%dT%H:%M:%SZ"),
-          "finished_at"      => nil},
         }]
     }}
   end
diff --git a/spec/v3/services/repositories/for_owner_spec.rb b/spec/v3/services/repositories/for_owner_spec.rb
index feca85ac..9dbdae21 100644
--- a/spec/v3/services/repositories/for_owner_spec.rb
+++ b/spec/v3/services/repositories/for_owner_spec.rb
@@ -63,7 +63,6 @@ describe Travis::API::V3::Services::Repositories::ForOwner, set_app: true do
           "@representation"  => "minimal",
           "name"             => "master"},
           "starred"          => false,
-          "current_build"    => nil
         }]}}
   end
 
@@ -140,8 +139,7 @@ describe Travis::API::V3::Services::Repositories::ForOwner, set_app: true do
           "@href"         => "/v3/repo/1/branch/master",
           "@representation"=>"minimal",
           "name"          => "master" },
-        "starred"         => false,
-        "current_build"   => nil }, {
+        "starred"         => false }, {
         "@type"           => "repository",
         "@href"           => "/v3/repo/#{repo2.id}",
         "@representation" => "standard",
@@ -170,7 +168,6 @@ describe Travis::API::V3::Services::Repositories::ForOwner, set_app: true do
           "@href"         => "/v3/repo/#{repo2.id}/branch/master",
           "@representation"=>"minimal",
           "name"           =>"master" },
-          "starred"        => false,
-          "current_build"  => nil}]}
+          "starred"        => false}]}
   end
 end
diff --git a/spec/v3/services/repository/find_spec.rb b/spec/v3/services/repository/find_spec.rb
index 0527d5e9..57683c3f 100644
--- a/spec/v3/services/repository/find_spec.rb
+++ b/spec/v3/services/repository/find_spec.rb
@@ -54,7 +54,6 @@ describe Travis::API::V3::Services::Repository::Find, set_app: true do
         "@representation"  => "minimal",
         "name"             => "master"},
       "starred"            => false,
-      "current_build"      => nil
     }}
   end
 
@@ -133,7 +132,6 @@ describe Travis::API::V3::Services::Repository::Find, set_app: true do
         "@representation"  => "minimal",
         "name"             => "master"},
       "starred"            => false,
-      "current_build"      => nil
     }}
   end
 
@@ -197,7 +195,6 @@ describe Travis::API::V3::Services::Repository::Find, set_app: true do
         "@representation"  => "minimal",
         "name"             => "master"},
       "starred"            => false,
-      "current_build"      => nil
     }}
   end
 
@@ -267,7 +264,6 @@ describe Travis::API::V3::Services::Repository::Find, set_app: true do
         "@representation"  => "minimal",
         "name"             => "master"},
       "starred"            => false,
-      "current_build"      => nil
     }}
   end