diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index 622201ac10d..f3dc7fbafe4 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -17223,7 +17223,8 @@ with pkgs;
   lean2 = callPackage ../applications/science/logic/lean2 {};
   lean3 = lean;
 
-  leo2 = callPackage ../applications/science/logic/leo2 {};
+  leo2 = callPackage ../applications/science/logic/leo2 {
+     ocaml = ocamlPackages_4_01_0.ocaml;};
 
   logisim = callPackage ../applications/science/logic/logisim {};