diff --git a/lib/jekyll/tags/post_url.rb b/lib/jekyll/tags/post_url.rb
index c8b820b8..b865cd67 100644
--- a/lib/jekyll/tags/post_url.rb
+++ b/lib/jekyll/tags/post_url.rb
@@ -14,7 +14,8 @@ module Jekyll
             "'#{name}' does not contain valid date and/or title."
         end
 
-        @name_regex = %r!^_posts/#{path}#{date}-#{slug}\.[^.]+|^#{path}_posts/?#{date}-#{slug}\.[^.]+!
+        @name_regex = %r!^_posts/#{path}#{date}-#{slug}\.[^.]+|
+          ^#{path}_posts/?#{date}-#{slug}\.[^.]+!x
       end
 
       def post_date
diff --git a/test/test_tags.rb b/test/test_tags.rb
index 5bfbd2f8..7a929281 100644
--- a/test/test_tags.rb
+++ b/test/test_tags.rb
@@ -596,19 +596,27 @@ title: Deprecated Post linking
 
 - 1 {% post_url 2008-11-21-nested %}
 CONTENT
-      create_post(content, {'permalink' => 'pretty', 'source' => source_dir, 'destination' => dest_dir, 'read_posts' => true})
+      create_post(content, {
+        "permalink"   => "pretty",
+        "source"      => source_dir,
+        "destination" => dest_dir,
+        "read_posts"  => true
+      })
     end
 
     should "not cause an error" do
-      refute_match(/markdown\-html\-error/, @result)
+      refute_match(%r!markdown\-html\-error!, @result)
     end
 
     should "have the url to the \"nested\" post from 2008-11-21" do
-      assert_match %r{1\s/2008/11/21/nested/}, @result
+      assert_match %r!1\s/2008/11/21/nested/!, @result
     end
 
     should "throw a deprecation warning" do
-      deprecation_warning = "       Deprecation: A call to '{{ post_url 2008-11-21-nested }}' did not match a post using the new matching method of checking name (path-date-slug) equality. Please make sure that you change this tag to match the post's name exactly."
+      deprecation_warning = "       Deprecation: A call to "\
+        "'{{ post_url 2008-11-21-nested }}' did not match a post using the new matching "\
+        "method of checking name (path-date-slug) equality. Please make sure that you "\
+        "change this tag to match the post's name exactly."
       assert_includes Jekyll.logger.messages, deprecation_warning
     end
   end