diff --git a/pkgs/development/coq-modules/waterproof/default.nix b/pkgs/development/coq-modules/waterproof/default.nix
index 313dd441e799..17ae9362bc5b 100644
--- a/pkgs/development/coq-modules/waterproof/default.nix
+++ b/pkgs/development/coq-modules/waterproof/default.nix
@@ -22,7 +22,7 @@ mkCoqDerivation {
       }
     ] null;
   release = {
-    "2.1.1+8.18".sha256 = "sha256-jYuQ9SPFRefNCUfn6+jEaJ4399EnU0gXPPkEDCpJYOI=";
+    "2.1.1+8.18".hash = "sha256-jYuQ9SPFRefNCUfn6+jEaJ4399EnU0gXPPkEDCpJYOI=";
   };
 
   propagatedBuildInputs = [ stdlib ];