diff --git a/activesupport/CHANGELOG.md b/activesupport/CHANGELOG.md
index 13d5fe3411..44735e4b75 100644
--- a/activesupport/CHANGELOG.md
+++ b/activesupport/CHANGELOG.md
@@ -1,3 +1,24 @@
+*   Fixed a roundtrip problem with AS::SafeBuffer where primitive-like strings
+    will be dumped as primitives:
+
+    Before:
+
+       YAML.load ActiveSupport::SafeBuffer.new("Hello").to_yaml  # => "Hello"
+       YAML.load ActiveSupport::SafeBuffer.new("true").to_yaml   # => true
+       YAML.load ActiveSupport::SafeBuffer.new("false").to_yaml  # => false
+       YAML.load ActiveSupport::SafeBuffer.new("1").to_yaml      # => 1
+       YAML.load ActiveSupport::SafeBuffer.new("1.1").to_yaml    # => 1.1
+
+     After:
+
+       YAML.load ActiveSupport::SafeBuffer.new("Hello").to_yaml  # => "Hello"
+       YAML.load ActiveSupport::SafeBuffer.new("true").to_yaml   # => "true"
+       YAML.load ActiveSupport::SafeBuffer.new("false").to_yaml  # => "false"
+       YAML.load ActiveSupport::SafeBuffer.new("1").to_yaml      # => "1"
+       YAML.load ActiveSupport::SafeBuffer.new("1.1").to_yaml    # => "1.1"
+
+    *Godfrey Chan*
+
 *   Enable number_to_percentage to keep the number's precision by allowing :precision to be nil
 
     *Jack Xu*
diff --git a/activesupport/lib/active_support/core_ext/string/output_safety.rb b/activesupport/lib/active_support/core_ext/string/output_safety.rb
index ff5712ed5d..bae4e206e6 100644
--- a/activesupport/lib/active_support/core_ext/string/output_safety.rb
+++ b/activesupport/lib/active_support/core_ext/string/output_safety.rb
@@ -222,7 +222,7 @@ module ActiveSupport #:nodoc:
     end
 
     def encode_with(coder)
-      coder.represent_scalar nil, to_str
+      coder.represent_object nil, to_str
     end
 
     UNSAFE_STRING_METHODS.each do |unsafe_method|
diff --git a/activesupport/test/safe_buffer_test.rb b/activesupport/test/safe_buffer_test.rb
index 4532152996..18fb6d2fbf 100644
--- a/activesupport/test/safe_buffer_test.rb
+++ b/activesupport/test/safe_buffer_test.rb
@@ -61,6 +61,13 @@ class SafeBufferTest < ActiveSupport::TestCase
     assert_equal({'str' => str}, YAML.load(yaml))
   end
 
+  test "Should work with primitive-like-strings in to_yaml conversion" do
+    assert_equal 'true',  YAML.load(ActiveSupport::SafeBuffer.new('true').to_yaml)
+    assert_equal 'false', YAML.load(ActiveSupport::SafeBuffer.new('false').to_yaml)
+    assert_equal '1',     YAML.load(ActiveSupport::SafeBuffer.new('1').to_yaml)
+    assert_equal '1.1',   YAML.load(ActiveSupport::SafeBuffer.new('1.1').to_yaml)
+  end
+
   test "Should work with underscore" do
     str = "MyTest".html_safe.underscore
     assert_equal "my_test", str