diff --git a/overlay.nix b/overlay.nix
index c1efa6177a24ea8a6023d54b475f34849fdc3f09..ed0cd89566f853ef2d02b33b38cb898874660fe5 100644
--- a/overlay.nix
+++ b/overlay.nix
@@ -151,6 +151,8 @@ final: prev: with pkgs.haskell.lib; {
 
   generics-sop = prev.callHackage "generics-sop" "0.5.1.2" { };
 
+  genvalidity-aeson = prev.callHackage "genvalidity-aeson" "1.0.0.1" { };
+
   genvalidity-bytestring = prev.callHackage "genvalidity-bytestring" "1.0.0.1" { };
 
   genvalidity-hspec = prev.callHackage "genvalidity-hspec" "1.0.0.2" { };