diff --git a/lib/jekyll-seo-tag/drop.rb b/lib/jekyll-seo-tag/drop.rb
index 06fe3a2..228bc3c 100644
--- a/lib/jekyll-seo-tag/drop.rb
+++ b/lib/jekyll-seo-tag/drop.rb
@@ -88,7 +88,7 @@ module Jekyll
                    end
 
           author["twitter"] ||= author["name"]
-          author["twitter"].delete! "@"
+          author["twitter"].delete! "@" if author["twitter"]
           author.to_liquid
         end
       end