diff --git a/actionview/lib/action_view/helpers/output_safety_helper.rb b/actionview/lib/action_view/helpers/output_safety_helper.rb
index e9febb8be9..25defd1276 100644
--- a/actionview/lib/action_view/helpers/output_safety_helper.rb
+++ b/actionview/lib/action_view/helpers/output_safety_helper.rb
@@ -60,7 +60,7 @@ module ActionView #:nodoc:
         when 2
           safe_join([array[0], array[1]], options[:two_words_connector])
         else
-          safe_join([safe_join(array[0...-1], options[:words_connector]), options[:last_word_connector], array[-1]])
+          safe_join([safe_join(array[0...-1], options[:words_connector]), options[:last_word_connector], array[-1]], nil)
         end
       end
     end
diff --git a/actionview/test/template/output_safety_helper_test.rb b/actionview/test/template/output_safety_helper_test.rb
index e3f515bb1c..0f3288130b 100644
--- a/actionview/test/template/output_safety_helper_test.rb
+++ b/actionview/test/template/output_safety_helper_test.rb
@@ -92,4 +92,14 @@ class OutputSafetyHelperTest < ActionView::TestCase
     assert_equal "one, two three", to_sentence(["one", "two", "three"], last_word_connector: " ")
     assert_equal "one, two and three", to_sentence(["one", "two", "three"], last_word_connector: " and ")
   end
+
+  test "to_sentence is not affected by $," do
+    $, = "|"
+    begin
+      assert_equal "one and two", to_sentence(["one", "two"])
+      assert_equal "one, two, and three", to_sentence(["one", "two", "three"])
+    ensure
+      $, = nil
+    end
+  end
 end