diff --git a/middleman-core/lib/middleman-core/core_extensions/file_watcher.rb b/middleman-core/lib/middleman-core/core_extensions/file_watcher.rb
index 62e9d3a4..a8d4a9a9 100644
--- a/middleman-core/lib/middleman-core/core_extensions/file_watcher.rb
+++ b/middleman-core/lib/middleman-core/core_extensions/file_watcher.rb
@@ -8,6 +8,7 @@ module Middleman
 
       IGNORE_LIST = [
         /^\.bundle\//,
+        /^vendor\//,
         /^\.sass-cache\//,
         /^\.git\//,
         /^\.gitignore$/,