diff --git a/pkgs/by-name/h2/h2o/package.nix b/pkgs/by-name/h2/h2o/package.nix
index d908919589d4..66f1e5712bef 100644
--- a/pkgs/by-name/h2/h2o/package.nix
+++ b/pkgs/by-name/h2/h2o/package.nix
@@ -13,7 +13,7 @@
   libuv,
   wslay,
   zlib,
-  withMruby ? false,
+  withMruby ? true,
   bison,
   ruby,
 }: