diff --git a/lib/sinatra/base.rb b/lib/sinatra/base.rb
index abff2d1f..dcde6bcd 100644
--- a/lib/sinatra/base.rb
+++ b/lib/sinatra/base.rb
@@ -1518,11 +1518,11 @@ module Sinatra
 
   # Extend the top-level DSL with the modules provided.
   def self.register(*extensions, &block)
-    Application.register(*extensions, &block)
+    Delegator.target.register(*extensions, &block)
   end
 
   # Include the helper modules provided in Sinatra's request context.
   def self.helpers(*extensions, &block)
-    Application.helpers(*extensions, &block)
+    Delegator.target.helpers(*extensions, &block)
   end
 end
diff --git a/test/delegator_test.rb b/test/delegator_test.rb
index 76f609e8..53de077f 100644
--- a/test/delegator_test.rb
+++ b/test/delegator_test.rb
@@ -46,7 +46,7 @@ class DelegatorTest < Test::Unit::TestCase
 
   def delegate(&block)
     assert Sinatra::Delegator.target != Sinatra::Application
-    Object.new.extend(Sinatra::Delegator).instance_eval(&block)
+    Object.new.extend(Sinatra::Delegator).instance_eval(&block) if block
     Sinatra::Delegator.target
   end
 
@@ -88,6 +88,18 @@ class DelegatorTest < Test::Unit::TestCase
     assert_equal '', response.body
   end
 
+  it "registers extensions with the delegation target" do
+    app, mixin = mirror, Module.new
+    Sinatra.register mixin
+    assert_equal app.last_call, ["register", mixin.to_s ]
+  end
+
+  it "registers helpers with the delegation target" do
+    app, mixin = mirror, Module.new
+    Sinatra.helpers mixin
+    assert_equal app.last_call, ["helpers", mixin.to_s ]
+  end
+
   delegates 'get'
   delegates 'patch'
   delegates 'put'