diff --git a/app/models/post.rb b/app/models/post.rb
index 7b2ff40..55a6f37 100644
--- a/app/models/post.rb
+++ b/app/models/post.rb
@@ -137,11 +137,11 @@ class Post
   end
 
   def tags
-    get_front_matter 'tags' || []
+    get_front_matter('tags') || []
   end
 
   def categories
-    get_front_matter 'categories' || []
+    get_front_matter('categories') || []
   end
   alias :category :categories