diff --git a/.travis.yml b/.travis.yml
index 0ebdf85..2c4a2d6 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -9,7 +9,7 @@ addons:
       - gcc-7
       - cppcheck
 before_install:
-    - sudo add-apt-repository ppa:team-gcc-arm-embedded/ppa
+    - sudo add-apt-repository -y ppa:team-gcc-arm-embedded/ppa
     - sudo apt-get update -q
     - sudo apt-get install -y gcc-arm-embedded
 script: