diff --git a/lib/jekyll/convertible.rb b/lib/jekyll/convertible.rb
index b9f7a93f..905afe57 100644
--- a/lib/jekyll/convertible.rb
+++ b/lib/jekyll/convertible.rb
@@ -112,11 +112,7 @@ module Jekyll
     #
     # Returns the Hash representation of this Convertible.
     def to_liquid(attrs = nil)
-      further_data = \
-        (attrs || self.class::ATTRIBUTES_FOR_LIQUID).each_with_object({}) do |attribute, hsh|
-          hsh[attribute] = send(attribute)
-        end
-
+      further_data = attribute_hash(attrs || self.class::ATTRIBUTES_FOR_LIQUID)
       Utils.deep_merge_hashes defaults, Utils.deep_merge_hashes(data, further_data)
     end
 
@@ -250,6 +246,13 @@ module Jekyll
       @defaults ||= site.frontmatter_defaults.all(relative_path, type)
     end
 
+    def attribute_hash(attrs)
+      @attribute_hash ||= {}
+      @attribute_hash[attrs] ||= attrs.each_with_object({}) do |attribute, hsh|
+        hsh[attribute] = send(attribute)
+      end
+    end
+
     def no_layout?
       data["layout"] == "none"
     end