1 files changed, 3 insertions, 3 deletions
diff --git a/lib/axlsx/drawing/str_data.rb b/lib/axlsx/drawing/str_data.rb
index 0765671f..5ab15c39 100644
--- a/lib/axlsx/drawing/str_data.rb
+++ b/lib/axlsx/drawing/str_data.rb
@@ -28,12 +28,12 @@ module Axlsx
 
     # serialize the object
     def to_xml_string(str = +'')
-      str << (+'<c:' << @tag_name.to_s << '>')
-      str << (+'<c:ptCount val="' << @pt.size.to_s << '"/>')
+      str << '<c:' << @tag_name.to_s << '>'
+      str << '<c:ptCount val="' << @pt.size.to_s << '"/>'
       @pt.each_with_index do |value, index|
         value.to_xml_string index, str
       end
-      str << (+'</c:' << @tag_name.to_s << '>')
+      str << '</c:' << @tag_name.to_s << '>'
     end
   end
 end