diff --git a/.travis.yml b/.travis.yml
index 2b2c7da..dff2a14 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,4 +1,5 @@
 language: ruby
+os: linux
 dist: xenial
 
 rvm:
@@ -16,8 +17,6 @@ env:
   - REDMINE_VER=4.0-stable DB=mysql
   - REDMINE_VER=master DB=mysql
 
-sudo: true
-
 notifications:
   webhooks:
     urls: