diff --git a/pkgs/development/tools/ocaml/opam/1.1.nix b/pkgs/development/tools/ocaml/opam/1.1.nix
index 9d16c6f1e81..c5093db107d 100644
--- a/pkgs/development/tools/ocaml/opam/1.1.nix
+++ b/pkgs/development/tools/ocaml/opam/1.1.nix
@@ -1,5 +1,8 @@
 { stdenv, fetchgit, fetchurl, ocaml, unzip, ncurses, curl }:
 
+# Opam 1.1 only works with ocaml >= 3.12.1 according to ./configure
+assert stdenv.lib.versionAtLeast (stdenv.lib.getVersion ocaml) "3.12.1";
+
 let
   srcs = {
     cudf = fetchurl {
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index ce38f2c4880..6a75135604d 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -3024,7 +3024,7 @@ let
     pycaml = callPackage ../development/ocaml-modules/pycaml { };
 
     opam_1_0_0 = callPackage ../development/tools/ocaml/opam/1.0.0.nix { };
-    opam_1_1 = callPackage ../development/tools/ocaml/opam/1.1.nix { ocaml = ocaml_4_01_0; };
+    opam_1_1 = callPackage ../development/tools/ocaml/opam/1.1.nix { };
     opam = opam_1_1;
   };