diff --git a/pkgs/applications/science/logic/coq/8.5.nix b/pkgs/applications/science/logic/coq/8.5.nix
index 104fb02fc45..1485626125d 100644
--- a/pkgs/applications/science/logic/coq/8.5.nix
+++ b/pkgs/applications/science/logic/coq/8.5.nix
@@ -6,7 +6,7 @@
 {stdenv, fetchurl, writeText, pkgconfig, ocaml, findlib, camlp5, ncurses, lablgtk ? null, csdp ? null}:
 
 let
-  version = "8.5";
+  version = "8.5pl1";
   coq-version = "8.5";
   buildIde = lablgtk != null;
   ideFlags = if buildIde then "-lablgtkdir ${lablgtk}/lib/ocaml/*/site-lib/lablgtk2 -coqide opt" else "";
@@ -23,8 +23,8 @@ stdenv.mkDerivation {
   inherit ocaml camlp5;
 
   src = fetchurl {
-    url = https://coq.inria.fr/distrib/V8.5/files/coq-8.5.tar.gz;
-    sha256 = "0gdfm6k5q1f8sz1xr9ijdkkvwqsb7v8prj21gmwv0z0yp6w2zac9";
+    url = "http://coq.inria.fr/distrib/V${version}/files/coq-${version}.tar.gz";
+    sha256 = "1w2xvm6w16khfn63bp95s25hnkn2ny3w0yqg3lq63gp11aqpbyjb";
   };
 
   buildInputs = [ pkgconfig ocaml findlib camlp5 ncurses lablgtk ];