write_xlsx.gemspec in write_xlsx-0.76.2 vs write_xlsx.gemspec in write_xlsx-0.76.3

@@ -14,10 +14,11 @@
 
   gem.files         = `git ls-files`.split($/)
   gem.executables   = gem.files.grep(%r{^bin/}).map{ |f| File.basename(f) }
   gem.test_files    = gem.files.grep(%r{^(test|spec|features)/})
   gem.require_paths = ["lib"]
-
+  gem.add_runtime_dependency 'rubyzip', '>= 1.0.0'
+  gem.add_runtime_dependency 'zip-zip'
   gem.extra_rdoc_files = [
     "LICENSE.txt",
     "README.md",
     "Changes"
   ]