diff --git a/.travis.yml b/.travis.yml
index ad4eb8c6..8a549510 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -14,7 +14,7 @@ before_script:
 
 install:
   - "sudo apt-get update -qq"
-  - "sudo apt-get install zsh"
+  - "sudo apt-get install -y zsh"
   - "sudo chsh -s $(which zsh)"
 
 script: