writeexcel.gemspec in writeexcel-1.0.7 vs writeexcel.gemspec in writeexcel-1.0.8

@@ -18,9 +18,10 @@
   gem.test_files    = gem.files.grep(%r{^(test|spec|features)/})
   gem.require_paths = ["lib"]
   gem.required_ruby_version = '>= 2.4.0'
   gem.add_development_dependency 'minitest'
   gem.add_runtime_dependency 'racc' if RUBY_VERSION >= '3.3'
+  gem.add_runtime_dependency 'nkf'
   gem.add_development_dependency 'rake'
   gem.extra_rdoc_files = [
     "LICENSE.txt",
     "README.rdoc"
   ]