diff --git a/activesupport/lib/active_support/hash_with_indifferent_access.rb b/activesupport/lib/active_support/hash_with_indifferent_access.rb
index 49aa01226869884111736595e5a46dccc3094697..91459f3e5b678db949257afb6ecac60de0e998c0 100644
--- a/activesupport/lib/active_support/hash_with_indifferent_access.rb
+++ b/activesupport/lib/active_support/hash_with_indifferent_access.rb
@@ -42,6 +42,10 @@ def self.new_from_hash_copying_default(hash)
       end
     end
 
+    def self.[](*args)
+      new.merge(Hash[*args])
+    end
+
     alias_method :regular_writer, :[]= unless method_defined?(:regular_writer)
     alias_method :regular_update, :update unless method_defined?(:regular_update)
 
diff --git a/activesupport/test/core_ext/hash_ext_test.rb b/activesupport/test/core_ext/hash_ext_test.rb
index 4544edf0ddd8358b10dda1723af927d2ea9c298f..80b3c16328ba8c340c106aed9043ff067a8bce1b 100644
--- a/activesupport/test/core_ext/hash_ext_test.rb
+++ b/activesupport/test/core_ext/hash_ext_test.rb
@@ -388,6 +388,15 @@ def test_store_on_indifferent_access
     assert_equal expected, hash
   end
 
+  def test_constructor_on_indifferent_access
+    hash = HashWithIndifferentAccess[:foo, 1]
+    assert_equal 1, hash[:foo]
+    assert_equal 1, hash['foo']
+    hash[:foo] = 3
+    assert_equal 3, hash[:foo]
+    assert_equal 3, hash['foo']
+  end
+
   def test_reverse_merge
     defaults = { :a => "x", :b => "y", :c => 10 }.freeze
     options  = { :a => 1, :b => 2 }