diff --git a/pkgs/applications/science/logic/why3/default.nix b/pkgs/applications/science/logic/why3/default.nix
index 0313467ed78..0eb51ff1620 100644
--- a/pkgs/applications/science/logic/why3/default.nix
+++ b/pkgs/applications/science/logic/why3/default.nix
@@ -2,15 +2,20 @@
 
 stdenv.mkDerivation rec {
   name    = "why3-${version}";
-  version = "0.86.2";
+  version = "0.86.3";
 
   src = fetchurl {
-    url    = https://gforge.inria.fr/frs/download.php/file/35214/why3-0.86.2.tar.gz;
-    sha256 = "08sa7dmp6yp29xn0m6h98nic4q47vb4ahvaid5drwh522pvwvg10";
+    url    = https://gforge.inria.fr/frs/download.php/file/35537/why3-0.86.3.tar.gz;
+    sha256 = "0sph6i4ga9450bk60wpm5cq3psw3g8xprnac7yjfq64iqz1dyz03";
   };
 
-  buildInputs = with ocamlPackages;
-    [ coq coq.camlp5 ocaml findlib lablgtk ocamlgraph zarith menhir ];
+  buildInputs = (with ocamlPackages; [
+      ocaml findlib lablgtk ocamlgraph zarith menhir ]) ++
+    stdenv.lib.optionals (ocamlPackages.ocaml == coq.ocaml ) [
+      coq coq.camlp5
+    ];
+
+  installTargets = [ "install" "install-lib" ];
 
   meta = with stdenv.lib; {
     description = "A platform for deductive program verification";
diff --git a/pkgs/development/ocaml-modules/why3/default.nix b/pkgs/development/ocaml-modules/why3/default.nix
deleted file mode 100644
index 3ce0f8bdfac..00000000000
--- a/pkgs/development/ocaml-modules/why3/default.nix
+++ /dev/null
@@ -1,21 +0,0 @@
-{ stdenv, ocaml, findlib, zarith, menhir, why3 }:
-
-let ocaml-version = stdenv.lib.getVersion ocaml; in
-
-assert stdenv.lib.versionAtLeast ocaml-version "4.01";
-
-stdenv.mkDerivation {
-  name = "ocaml-${why3.name}";
-
-  inherit (why3) src;
-
-  buildInputs = [ ocaml findlib zarith menhir ];
-
-  installTargets = "install-lib";
-
-  meta = {
-    inherit (why3.meta) license homepage;
-    platforms = ocaml.meta.platforms;
-    maintainers = with stdenv.lib.maintainers; [ vbgl ];
-  };
-}
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index e45a7466aaf..4aaaaf2ae1f 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -5042,10 +5042,6 @@ let
 
     vg = callPackage ../development/ocaml-modules/vg { };
 
-    why3 = callPackage ../development/ocaml-modules/why3 {
-      why3 = pkgs.why3;
-    };
-
     x509 = callPackage ../development/ocaml-modules/x509 { };
 
     xmlm = callPackage ../development/ocaml-modules/xmlm { };