diff --git a/pkgs/development/libraries/libmpack/default.nix b/pkgs/development/libraries/libmpack/default.nix
index b62da40499c..3ec800f890f 100644
--- a/pkgs/development/libraries/libmpack/default.nix
+++ b/pkgs/development/libraries/libmpack/default.nix
@@ -12,7 +12,7 @@ stdenv.mkDerivation rec {
 
   nativeBuildInputs = [ libtool ];
 
-  makeFlags = [ "LIBTOOL=libtool" "PREFIX=$(out)" ];
+  makeFlags = [ "LIBTOOL=libtool" "PREFIX=$(out)" "config=release" ];
 
   meta = with lib; {
     description = "Simple implementation of msgpack in C";