diff --git a/.travis.yml b/.travis.yml
index fe9e2d1..21b998f 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -3,3 +3,7 @@ script:
     - git clone --depth 1 https://github.com/NixOS/nixpkgs ../nixpkgs
     - nix-build tests/intern.nix
     - nix-build tests/extern.nix
+
+cache:
+  directories:
+      - /nix/store