diff --git a/Guardfile b/Guardfile
index b700ee4..686f6bf 100644
--- a/Guardfile
+++ b/Guardfile
@@ -21,4 +21,5 @@ guard 'nanoc' do
   watch('nanoc.yaml') # Change this to config.yaml if you use the old config file name
   watch('Rules')
   watch(%r{^(content|layouts|lib)/.*$})
+  ignore(%r{^content/main\.(js|css|js\.map|css\.map)})
 end