diff --git a/pkgs/development/interpreters/ruby/ruby-19.nix b/pkgs/development/interpreters/ruby/ruby-19.nix
index 5e406509a8c..f47d0e524f7 100644
--- a/pkgs/development/interpreters/ruby/ruby-19.nix
+++ b/pkgs/development/interpreters/ruby/ruby-19.nix
@@ -4,7 +4,7 @@
 , gdbm, gdbmSupport ? true
 , ncurses, readline, cursesSupport ? false
 , groff, docSupport ? false
-, libyaml, yamlSupport ? false
+, libyaml, yamlSupport ? true
 }:
 
 let