diff --git a/lib/spring/application.rb b/lib/spring/application.rb
index 6d23d8fa..42ef54d8 100644
--- a/lib/spring/application.rb
+++ b/lib/spring/application.rb
@@ -117,7 +117,7 @@ def preload
       raise e unless initialized?
     ensure
       watcher.add loaded_application_features
-      watcher.add Spring.gemfile, "#{Spring.gemfile}.lock"
+      watcher.add Spring.gemfile, Spring.gemfile_lock
 
       if defined?(Rails) && Rails.application
         watcher.add Rails.application.paths["config/initializers"]
diff --git a/lib/spring/configuration.rb b/lib/spring/configuration.rb
index eba8e9a7..e7d4defb 100644
--- a/lib/spring/configuration.rb
+++ b/lib/spring/configuration.rb
@@ -6,12 +6,21 @@ class << self
 
     def gemfile
       if /\s1.9.[0-9]/ ===  Bundler.ruby_scope.gsub(/[\/\s]+/,'')
-        ENV["BUNDLE_GEMFILE"] || "Gemfile"
+        Pathname.new(ENV["BUNDLE_GEMFILE"] || "Gemfile").expand_path
       else
         Bundler.default_gemfile
       end
     end
 
+    def gemfile_lock
+      case gemfile.to_s
+      when /\bgems\.rb\z/
+        gemfile.sub_ext('.locked')
+      else
+        gemfile.sub_ext('.lock')
+      end
+    end
+
     def after_fork_callbacks
       @after_fork_callbacks ||= []
     end