diff --git a/lib/strings.nix b/lib/strings.nix
index 39112407c570..ee5a59bdaf80 100644
--- a/lib/strings.nix
+++ b/lib/strings.nix
@@ -47,7 +47,9 @@ rec {
 
   # Construct a library search path (such as RPATH) containing the
   # libraries for a set of packages, e.g. "${pkg1}/lib:${pkg2}/lib:...".
-  makeLibraryPath = makeSearchPath "lib";
+  makeLibraryPath = pkgs: makeSearchPath "lib"
+    # try to guess the right output of each pkg
+    (map (pkg: pkg.lib or (pkg.out or pkg)) pkgs);
 
 
   # Idem for Perl search paths.
diff --git a/nixos/modules/config/system-path.nix b/nixos/modules/config/system-path.nix
index d22f9ebd1dfd..58ebea1dabc2 100644
--- a/nixos/modules/config/system-path.nix
+++ b/nixos/modules/config/system-path.nix
@@ -115,7 +115,15 @@ in
 
     system.path = pkgs.buildEnv {
       name = "system-path";
-      paths = config.environment.systemPackages;
+      paths = let
+        #outputs TODO: make it user-customizable?
+        pkgOutputFun = pkg: lib.filter (p: p!=null) [
+          (pkg.bin or (pkg.out or pkg))
+          (pkg.man or null)
+          (pkg.info or null)
+          (pkg.doc or null)
+        ];
+        in lib.concatMap pkgOutputFun config.environment.systemPackages;
       inherit (config.environment) pathsToLink;
       ignoreCollisions = true;
       # !!! Hacky, should modularise.