diff --git a/lib/jekyll-seo-tag/drop.rb b/lib/jekyll-seo-tag/drop.rb
index 7656b06..fd16c1f 100644
--- a/lib/jekyll-seo-tag/drop.rb
+++ b/lib/jekyll-seo-tag/drop.rb
@@ -183,7 +183,7 @@ module Jekyll
 
       def canonical_url
         @canonical_url ||= begin
-          if page["canonical_url"].present?
+          if !page["canonical_url"].to_s.empty?
             page["canonical_url"]
           else
             filters.absolute_url(page["url"]).to_s.gsub(%r!/index\.html$!, "/")