diff --git a/pkgs/tools/networking/haproxy/default.nix b/pkgs/tools/networking/haproxy/default.nix
index 3b7a68fb972f..88c750525b26 100644
--- a/pkgs/tools/networking/haproxy/default.nix
+++ b/pkgs/tools/networking/haproxy/default.nix
@@ -15,9 +15,17 @@ stdenv.mkDerivation rec {
   buildInputs = [ openssl zlib ];
 
   # TODO: make it work on bsd as well
-  preConfigure = ''
-    export makeFlags="TARGET=${if stdenv.isSunOS then "solaris" else if stdenv.isLinux then "linux2628" else "generic"} PREFIX=$out USE_OPENSSL=yes USE_ZLIB=yes ${stdenv.lib.optionalString stdenv.isDarwin "CC=cc USE_KQUEUE=1"}"
-  '';
+  makeFlags = [
+    "PREFIX=\${out}"
+    ("TARGET=" + (if stdenv.isSunOS  then "solaris"
+             else if stdenv.isLinux  then "linux2628"
+             else if stdenv.isDarwin then "osx"
+             else "generic"))
+  ];
+  buildFlags = [
+    "USE_OPENSSL=yes"
+    "USE_ZLIB=yes"
+  ] ++ stdenv.lib.optional stdenv.isDarwin "CC=cc";
 
   meta = {
     description = "Reliable, high performance TCP/HTTP load balancer";