diff --git a/middleman-core/lib/middleman-core/preview_server.rb b/middleman-core/lib/middleman-core/preview_server.rb
index 93934478..ce127b5f 100644
--- a/middleman-core/lib/middleman-core/preview_server.rb
+++ b/middleman-core/lib/middleman-core/preview_server.rb
@@ -163,14 +163,16 @@ module Middleman
                                   path: root,
                                   only: match_against
 
-            # Hack around node_modules in root.
-            watcher.listener.ignore(/^node_modules/)
+            unless config[:watcher_disable]
+              # Hack around node_modules in root.
+              watcher.listener.ignore(/^node_modules/)
 
-            # Hack around sass cache in root.
-            watcher.listener.ignore(/^\.sass-cache/)
+              # Hack around sass cache in root.
+              watcher.listener.ignore(/^\.sass-cache/)
 
-            # Hack around bundler cache in root.
-            watcher.listener.ignore(/^vendor\/bundle/)
+              # Hack around bundler cache in root.
+              watcher.listener.ignore(/^vendor\/bundle/)
+            end
           end
         end