diff --git a/.nix/config.nix b/.nix/config.nix
index 1b6ecd1ed..6f89b1da6 100644
--- a/.nix/config.nix
+++ b/.nix/config.nix
@@ -32,7 +32,13 @@
       reglang.job = false;
     };
 
+    "coq-master".ocamlPackages = {
+      elpi.override.version = "v1.19.2";
+    };
+
     "coq-master".coqPackages = {
+
+      coq.override.version = "gares:demote-demote";
       
       hierarchy-builder.override.version = "master";
       hierarchy-builder-shim.job = false;