diff --git a/.travis.yml b/.travis.yml
index 65e30d80..93f7a625 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -3,6 +3,10 @@ branches:
   except:
     - debug
 node_js:
+  - 4
   - 6
   - 8
   - 10
+cache:
+  directories:
+    - node_modules
\ No newline at end of file