diff --git a/dev-ruby/cgi/cgi-0.5.1.ebuild b/dev-ruby/cgi/cgi-0.5.1.ebuild
index e1f00ace9ff4..c5e025e29843 100644
--- a/dev-ruby/cgi/cgi-0.5.1.ebuild
+++ b/dev-ruby/cgi/cgi-0.5.1.ebuild
@@ -3,7 +3,7 @@
 
 EAPI=8
 
-USE_RUBY="ruby32 ruby33 ruby34"
+USE_RUBY="ruby32 ruby33 ruby34 ruby40"
 
 RUBY_FAKEGEM_EXTENSIONS=(ext/cgi/escape/extconf.rb)
 RUBY_FAKEGEM_EXTENSION_LIBDIR=lib/cgi