diff --git a/plugins/category_generator.rb b/plugins/category_generator.rb
index 4b279e0..09491c3 100644
--- a/plugins/category_generator.rb
+++ b/plugins/category_generator.rb
@@ -128,7 +128,7 @@ module Jekyll
 ===============================================
  Error for category_generator.rb plugin
 -----------------------------------------------
- No 'category_index.hmtl' in source/_layouts/
+ No 'category_index.html' in source/_layouts/
  Perhaps you haven't installed a theme yet.
 ===============================================