diff --git a/lib/nesta/static/site.rb b/lib/nesta/static/site.rb
index 406d672a..70acb6d1 100644
--- a/lib/nesta/static/site.rb
+++ b/lib/nesta/static/site.rb
@@ -61,8 +61,8 @@ def log(message)
 
       def set_app_root
         root = ::File.expand_path('.')
-        ['Gemfile', ].each do |expected|
-          if ! File.exist?(File.join(root, 'config', 'config.yml'))
+        ['Gemfile', File.join('config', 'config.yml')].each do |expected|
+          if ! File.exist?(File.join(root, expected))
             message = "is this a Nesta site? (expected './#{expected}')"
             raise RuntimeError, message
           end
diff --git a/test/support/temporary_files.rb b/test/support/temporary_files.rb
index e20ecf51..c1af68a1 100644
--- a/test/support/temporary_files.rb
+++ b/test/support/temporary_files.rb
@@ -1,3 +1,5 @@
+require 'fileutils'
+
 module TemporaryFiles
   TEMP_DIR = File.expand_path('tmp', File.join(File.dirname(__FILE__), '..'))
 
@@ -21,7 +23,8 @@ def project_path(path)
 
   def in_temporary_project(*args, &block)
     FileUtils.mkdir_p(File.join(project_root, 'config'))
-    File.open(File.join(project_root, 'config', 'config.yml'), 'w').close
+    FileUtils.touch(File.join(project_root, 'Gemfile'))
+    FileUtils.touch(File.join(project_root, 'config', 'config.yml'))
     Dir.chdir(project_root) { yield project_root }
   ensure
     remove_temp_directory