diff --git a/.travis.yml b/.travis.yml
index d28133b..49d7e76 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,9 +1,9 @@
 sudo: false
 language: node_js
 node_js:
-    - 8
-    - 9
-    - 10
+    - "8"
+    - "9"
+    - "10"
 services:
     - mongodb
 cache: