tasks/test.rake in nanoc-4.1.1 vs tasks/test.rake in nanoc-4.1.2

@@ -2,10 +2,10 @@
 require 'rake/testtask'
 require 'coveralls/rake/task'
 
 Coveralls::RakeTask.new
 
-SUBDIRS = %w( * base cli data_sources extra filters helpers )
+SUBDIRS = %w( * base cli data_sources extra filters helpers ).freeze
 
 namespace :test do
   SUBDIRS.each do |dir|
     Rake::TestTask.new(dir == '*' ? 'all' : dir) do |t|
       t.test_files = Dir["test/#{dir}/**/*_spec.rb"] + Dir["test/#{dir}/**/test_*.rb"]