diff --git a/activesupport/lib/active_support/tagged_logging.rb b/activesupport/lib/active_support/tagged_logging.rb
index 974c42ebba..5e080df518 100644
--- a/activesupport/lib/active_support/tagged_logging.rb
+++ b/activesupport/lib/active_support/tagged_logging.rb
@@ -31,7 +31,7 @@ module ActiveSupport
       def tags_text
         tags = current_tags
         if tags.any?
-          tags.collect { |tag| "[#{tag}] " }.join('')
+          tags.collect { |tag| "[#{tag}] " }.join
         end
       end
     end
diff --git a/activesupport/test/tagged_logging_test.rb b/activesupport/test/tagged_logging_test.rb
index 732a28c56f..0751c2469e 100644
--- a/activesupport/test/tagged_logging_test.rb
+++ b/activesupport/test/tagged_logging_test.rb
@@ -10,13 +10,8 @@ class TaggedLoggingTest < ActiveSupport::TestCase
   end
 
   setup do
-    @output     = StringIO.new
-    @logger     = ActiveSupport::TaggedLogging.new(MyLogger.new(@output))
-    @separator  = $,
-  end
-
-  after do
-    $, = @separator
+    @output = StringIO.new
+    @logger = ActiveSupport::TaggedLogging.new(MyLogger.new(@output))
   end
 
   test "tagged once" do
@@ -74,10 +69,4 @@ class TaggedLoggingTest < ActiveSupport::TestCase
 
     assert_equal "[BCX] [Jason] Funky time\n[BCX] Junky time!\n", @output.string
   end
-
-  test "using the correct separator" do
-    $, = "_"
-    @logger.tagged("BCX", "BDX") { @logger.info "Funky time" }
-    assert_equal "[BCX] [BDX] Funky time\n", @output.string
-  end
 end