diff --git a/lib/jekyll/frontmatter_defaults.rb b/lib/jekyll/frontmatter_defaults.rb
index 0614975a..7cbfa358 100644
--- a/lib/jekyll/frontmatter_defaults.rb
+++ b/lib/jekyll/frontmatter_defaults.rb
@@ -188,7 +188,7 @@ module Jekyll
       if path.nil? || path.empty?
         ""
       else
-        path.gsub(%r!\A/!, "").gsub(%r!([^/])\z!, '\1')
+        path.gsub(%r!\A/|(?<=[^/])\z!, "".freeze)
       end
     end
   end
diff --git a/lib/jekyll/readers/data_reader.rb b/lib/jekyll/readers/data_reader.rb
index 370a6893..0afbad61 100644
--- a/lib/jekyll/readers/data_reader.rb
+++ b/lib/jekyll/readers/data_reader.rb
@@ -62,8 +62,7 @@ module Jekyll
     end
 
     def sanitize_filename(name)
-      name.gsub!(%r![^\w\s-]+!, "")
-      name.gsub!(%r!(^|\b\s)\s+($|\s?\b)!, '\\1\\2')
+      name.gsub!(%r![^\w\s-]+|(?<=^|\b\s)\s+(?=$|\s?\b)!, "".freeze)
       name.gsub(%r!\s+!, "_")
     end
   end