diff --git a/pkgs/tools/networking/vpnc/builder.sh b/pkgs/tools/networking/vpnc/builder.sh
new file mode 100644
index 000000000000..ecfabe2eb5e6
--- /dev/null
+++ b/pkgs/tools/networking/vpnc/builder.sh
@@ -0,0 +1,9 @@
+source "$stdenv/setup"
+
+tar zxvf "$src" &&
+cd vpnc-*.*
+
+cat config.c |								\
+sed "s|/etc/vpnc/vpnc-script|$out/etc/vpnc/vpnc-script|g" > ,,tmp &&	\
+mv ,,tmp config.c &&							\
+patchPhase && buildPhase && installPhase && fixupPhase && distPhase
diff --git a/pkgs/tools/networking/vpnc/default.nix b/pkgs/tools/networking/vpnc/default.nix
index 87e43ee7eed1..c11a4721cb74 100644
--- a/pkgs/tools/networking/vpnc/default.nix
+++ b/pkgs/tools/networking/vpnc/default.nix
@@ -10,6 +10,7 @@ stdenv.mkDerivation {
   patches = [ ./makefile.patch ];
 
   buildInputs = [libgcrypt perl];
+  builder = ./builder.sh;
 
   meta = {
     description = "VPNC, a virtual private network (VPN) client for Cisco's VPN concentrators";