diff --git a/lib/jekyll/tags/post_url.rb b/lib/jekyll/tags/post_url.rb
index 04c1ef29..c8b820b8 100644
--- a/lib/jekyll/tags/post_url.rb
+++ b/lib/jekyll/tags/post_url.rb
@@ -14,7 +14,7 @@ module Jekyll
             "'#{name}' does not contain valid date and/or title."
         end
 
-        @name_regex = %r!^#{path}#{date}-#{slug}\.[^.]+!
+        @name_regex = %r!^_posts/#{path}#{date}-#{slug}\.[^.]+|^#{path}_posts/?#{date}-#{slug}\.[^.]+!
       end
 
       def post_date
@@ -23,7 +23,7 @@ module Jekyll
       end
 
       def ==(other)
-        other.basename.match(@name_regex)
+        other.relative_path.match(@name_regex)
       end
 
       def deprecated_equality(other)