diff --git a/lib/liquid/tag.rb b/lib/liquid/tag.rb
index 2f7bc301..8303a723 100644
--- a/lib/liquid/tag.rb
+++ b/lib/liquid/tag.rb
@@ -54,7 +54,8 @@ module Liquid
     # of the `render_to_output_buffer` method will become the default and the `render`
     # method will be removed.
     def render_to_output_buffer(context, output)
-      output << render(context)
+      render_result = render(context)
+      output << render_result if render_result
       output
     end
 
diff --git a/test/unit/tag_unit_test.rb b/test/unit/tag_unit_test.rb
index b814b1b7..7f9b490c 100644
--- a/test/unit/tag_unit_test.rb
+++ b/test/unit/tag_unit_test.rb
@@ -20,4 +20,13 @@ class TagUnitTest < Minitest::Test
     tag = Tag.parse("some_tag", "", Tokenizer.new(""), ParseContext.new)
     assert_equal('some_tag', tag.tag_name)
   end
+
+  class CustomTag < Liquid::Tag
+    def render(_context); end
+  end
+
+  def test_tag_render_to_output_buffer_nil_value
+    custom_tag = CustomTag.parse("some_tag", "", Tokenizer.new(""), ParseContext.new)
+    assert_equal('some string', custom_tag.render_to_output_buffer(Context.new, "some string"))
+  end
 end