diff --git a/overlay.nix b/overlay.nix
index 902edda9295894e49fb3e7c669f811192739643d..27a4071b3c7f4ed606a4a445c436533cb081424a 100644
--- a/overlay.nix
+++ b/overlay.nix
@@ -199,6 +199,8 @@ final: prev: with pkgs.haskell.lib; {
 
   singleton-bool = doJailbreak prev.singleton-bool;
 
+  singletons = prev.callHackage "singletons" "3.0.2" { };
+
   some = doJailbreak prev.some;
 
   sop-core = doJailbreak prev.sop-core;