diff --git a/pkgs/development/libraries/science/math/openblas/default.nix b/pkgs/development/libraries/science/math/openblas/default.nix
index bd095a11f088..91162ba5465a 100644
--- a/pkgs/development/libraries/science/math/openblas/default.nix
+++ b/pkgs/development/libraries/science/math/openblas/default.nix
@@ -76,11 +76,10 @@ let
     if blas64_ != null
       then blas64_
       else hasPrefix "x86_64" stdenv.system;
-
-  version = "0.3.0";
 in
-stdenv.mkDerivation {
+stdenv.mkDerivation rec {
   name = "openblas-${version}";
+  version = "0.3.0";
   src = fetchurl {
     url = "https://github.com/xianyi/OpenBLAS/archive/v${version}.tar.gz";
     sha256 = "18giv3lsh8cva01z4rhsx8jvgliknni0jp7vxkc69qxb14vm8lfg";