diff --git a/default.nix b/default.nix
index 89d773a..3dc3816 100644
--- a/default.nix
+++ b/default.nix
@@ -4,8 +4,7 @@ with pkgs;
 
 let
 
-  # FIXME
-  nix = builtins.storePath /nix/store/cvrdgdx0gzdi0yf2831f4j98d518m3ln-nix-1.12pre1234_abcdef;
+  nix = nixUnstable;
   #lib.overrideDerivation nixUnstable (orig: {
   #  src = /home/eelco/Dev/nix;
   #});
@@ -16,13 +15,17 @@ stdenv.mkDerivation {
   name = "nixos-channel-scripts";
 
   buildInputs = with perlPackages;
-    [ nix sqlite makeWrapper perl FileSlurp LWP LWPProtocolHttps ListMoreUtils DBDSQLite NetAmazonS3 boehmgc nlohmann_json ];
+    [ pkgconfig nix sqlite makeWrapper perl FileSlurp LWP LWPProtocolHttps ListMoreUtils DBDSQLite NetAmazonS3 boehmgc nlohmann_json ];
 
   buildCommand = ''
     mkdir -p $out/bin
 
-    g++ -g ${./generate-programs-index.cc} -Wall -std=c++11 -o $out/bin/generate-programs-index \
-      -I ${nix}/include/nix -lnixmain -lnixexpr -lnixformat -lsqlite3 -lgc -I .
+    g++ -g ${./generate-programs-index.cc} -Wall -std=c++14 -o $out/bin/generate-programs-index \
+      $(pkg-config --cflags nix-main) \
+      $(pkg-config --libs nix-main) \
+      $(pkg-config --libs nix-expr) \
+      $(pkg-config --libs nix-store) \
+      -lsqlite3 -lgc
 
     cp ${./mirror-nixos-branch.pl} $out/bin/mirror-nixos-branch
     wrapProgram $out/bin/mirror-nixos-branch --set PERL5LIB $PERL5LIB --prefix PATH : ${wget}/bin:${git}/bin:${nix}/bin:${gnutar}/bin:${xz}/bin:$out/bin
diff --git a/generate-programs-index.cc b/generate-programs-index.cc
index 7544f18..c155490 100644
--- a/generate-programs-index.cc
+++ b/generate-programs-index.cc
@@ -1,3 +1,5 @@
+#include <nix/config.h>
+
 #include <chrono>
 #include <regex>