diff --git a/.travis.yml b/.travis.yml
index d8a52c6..84dd736 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,7 +1,7 @@
 language: cpp
 compiler: gcc
 before_install:
-  - sudo add-apt-repository ppa:coolwanglu/pdf2htmlex
+  - sudo add-apt-repository ppa:coolwanglu/pdf2htmlex --yes
   - sudo apt-get update -qq
   - sudo apt-get install -qq libpoppler-dev libfontforge-dev libspiro-dev
 before_script: