diff --git a/.travis.yml b/.travis.yml
index 7e1193e..46eb519 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,8 +1,9 @@
 language: ruby
 script: "bundle exec rspec spec"
 env:
-  - NOKOGIRI_USE_SYSTEM_LIBRARIES=true
   - CI=true
+  global:
+    - NOKOGIRI_USE_SYSTEM_LIBRARIES=true
 rvm:
   - 2.4
   - 2.5