Template payload should be a UnifiedPayloadDrop, not a hash

lib/jekyll-seo-tag.rb

@@ -44,12 +44,12 @@ module Jekyll
     end
 
     def payload
-      {
+      # site_payload is an instance of UnifiedPayloadDrop. See https://git.io/v5ajm
+      @payload ||= context.registers[:site].site_payload.merge({
         "page"      => context.registers[:page],
-        "site"      => context.registers[:site].site_payload["site"],
         "paginator" => context["paginator"],
         "seo_tag"   => drop,
-      }
+      })
     end
 
     def drop

lib/jekyll-seo-tag/drop.rb

@@ -20,10 +20,6 @@ module Jekyll
         Jekyll::SeoTag::VERSION
       end
 
-      def jekyll_version
-        Jekyll::VERSION
-      end
-
       # Should the `<title>` tag be generated for this page?
       def title?
         return false unless title

lib/template.html

@@ -3,7 +3,7 @@
   <title>{{ seo_tag.title }}</title>
 {% endif %}
 
-<meta name="generator" content="Jekyll v{{ seo_tag.jekyll_version }}" />
+<meta name="generator" content="Jekyll v{{ jekyll.version }}" />
 
 {% if seo_tag.page_title %}
   <meta property="og:title" content="{{ seo_tag.page_title }}" />