diff --git a/.travis.yml b/.travis.yml
index e1d61177407fc115c950385483068fd97cb83c2a..66ece26cb778b3d8812bf2efa33fbc4c0c2171bb 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -23,7 +23,7 @@  - travis_retry nix-channel --update
 
 script:
 
-language: nix
+  include:
  - nix eval -f default.nix 'lib'
  - nix eval -f default.nix 'modules'
  - nix eval -f default.nix 'overlays'
diff --git a/buildable.nix b/buildable.nix
deleted file mode 100644
index 2b61b1f7627f912a2597c1369e0cd97f7c27eac4..0000000000000000000000000000000000000000
--- a/buildable.nix
+++ /dev/null
@@ -1,28 +0,0 @@
-# This file filters out all the unbuildable packages from your package set.
-# It's what gets built by CI, so if you correctly mark broken/unfree packages
-# as such your CI will not try to build them and the buildable packages will
-# be added to the cache.
-{ pkgs ? import <nixpkgs> {} }:
-
-let
-  filterSet =
-    (f: g: s: builtins.listToAttrs
-      (map
-        (n: { name = n; value = builtins.getAttr n s; })
-        (builtins.filter
-          (n: f n && g (builtins.getAttr n s))
-          (builtins.attrNames s)
-        )
-      )
-    );
-  isReserved = n: builtins.elem n ["lib" "overlays" "modules"];
-  isBroken = p: p.meta.broken or false;
-  isFree = p: p.meta.license.free or true;
-in filterSet
-     (n: !(isReserved n)) # filter out non-packages
-     (p: (builtins.isAttrs p)
-       && !(isBroken p)
-       && isFree p
-     )
-     (import ./default.nix { inherit pkgs; })
-
diff --git a/non-broken.nix b/non-broken.nix
new file mode 100644
index 0000000000000000000000000000000000000000..b9a2cf9c6501ea634a8dd95428f855501b436b61
--- /dev/null
+++ b/non-broken.nix
@@ -0,0 +1,27 @@
+# This file filters out all the broken packages from your package set.
+# It's what gets built by CI, so if you correctly mark broken packages as
+# broken your CI will not try to build them and the non-broken packages will
+# be added to the cache.
+{ pkgs ? import <nixpkgs> {} }:
+
+let filterSet =
+      (f: g: s: builtins.listToAttrs
+        (map
+          (n: { name = n; value = builtins.getAttr n s; })
+          (builtins.filter
+            (n: f n && g (builtins.getAttr n s))
+            (builtins.attrNames s)
+          )
+        )
+      );
+in filterSet
+     (n: !(n=="lib"||n=="overlays"||n=="modules")) # filter out non-packages
+     (p: (builtins.isAttrs p)
+       && !(
+             (builtins.hasAttr "meta" p)
+             && (builtins.hasAttr "broken" p.meta)
+             && (p.meta.broken)
+           )
+     )
+     (import ./default.nix { inherit pkgs; })
+
diff --git a/overlay.nix b/overlay.nix
index bda4332a081fcd8c713733a27a02f0dc312cd32c..082b03836fd169bc00f6093001bf9c51459c999c 100644
--- a/overlay.nix
+++ b/overlay.nix
@@ -4,22 +4,20 @@ # to your configuration.
 
 self: super:
 
-let
+let filterSet =
-  filterSet =
+      (f: g: s: builtins.listToAttrs
-    (f: g: s: builtins.listToAttrs
+        (map
-      (map
+          (n: { name = n; value = builtins.getAttr n s; })
-        (n: { name = n; value = builtins.getAttr n s; })
+          (builtins.filter
-        (builtins.filter
+            (n: f n && g (builtins.getAttr n s))
-# You can use this file as a nixpkgs overlay.
 # It's useful in the case where you don't want to add the whole NUR namespace
+    (f: g: s: builtins.listToAttrs
-          (builtins.attrNames s)
+          )
         )
-      )
-    );
-  isReserved = n: builtins.elem n ["lib" "overlays" "modules"];
+      );
 in filterSet
+# to your configuration.
 # You can use this file as a nixpkgs overlay.
-      (map
      (p: true) # all packages are ok
      (import ./default.nix { pkgs = super; })