diff --git a/pkgs/applications/science/logic/abella/default.nix b/pkgs/applications/science/logic/abella/default.nix
index 210211a6b948..5902450717b6 100644
--- a/pkgs/applications/science/logic/abella/default.nix
+++ b/pkgs/applications/science/logic/abella/default.nix
@@ -13,10 +13,11 @@ stdenv.mkDerivation (finalAttrs: {
 
   src = fetchurl {
     url = "http://abella-prover.org/distributions/abella-${finalAttrs.version}.tar.gz";
-    sha256 = "sha256-80b/RUpE3KRY0Qu8eeTxAbk6mwGG6jVTPOP0qFjyj2M=";
+    hash = "sha256-80b/RUpE3KRY0Qu8eeTxAbk6mwGG6jVTPOP0qFjyj2M=";
   };
 
   strictDeps = true;
+  __structuredAttrs = true;
 
   nativeBuildInputs = [
     rsync
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index 89e8ab34a9ae..e1804ddd67af 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -10513,9 +10513,7 @@ with pkgs;
 
   ### SCIENCE/LOGIC
 
-  abella = callPackage ../applications/science/logic/abella {
-    ocamlPackages = ocaml-ng.ocamlPackages_4_12;
-  };
+  abella = callPackage ../applications/science/logic/abella { };
 
   inherit
     (callPackage ./rocq-packages.nix {