diff --git a/lib/xcode/install.rb b/lib/xcode/install.rb
index 78f25bb..696ec97 100644
--- a/lib/xcode/install.rb
+++ b/lib/xcode/install.rb
@@ -380,7 +380,7 @@ def get_dmg(version, progress = true, url = nil, progress_block = nil, retry_dow
       end
       if ENV.key?('XCODE_INSTALL_CACHE_DIR')
         Pathname.glob(ENV['XCODE_INSTALL_CACHE_DIR'] + '/*').each do |fpath|
-          return fpath if /^xcode_#{version}\.dmg|xip$/ =~ fpath.basename.to_s
+          return fpath if /^xcode_#{version}\.(dmg|xip)$/i =~ fpath.basename.to_s
         end
       end