diff --git a/templates/default/onefile/html/setup.rb b/templates/default/onefile/html/setup.rb
index fa94d320a..cd82aea14 100644
--- a/templates/default/onefile/html/setup.rb
+++ b/templates/default/onefile/html/setup.rb
@@ -41,7 +41,7 @@ def parse_top_comments_from_file
   tokens = TokenList.new(@readme.contents)
   tokens.each do |token|
     break unless token.is_a?(RubyToken::TkCOMMENT) || token.is_a?(RubyToken::TkNL)
-    data << (token.text[/\A#\s{0,1}(.*)/, 1] || "\n")
+    data += (token.text[/\A#\s{0,1}(.*)/, 1] || "\n")
   end
   YARD::Docstring.new(data)
 end