diff --git a/.travis.yml b/.travis.yml
index 3227a12..2c87065 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -20,6 +20,7 @@ matrix:
 
 before_install:
   - composer install --ansi --prefer-dist --no-interaction --optimize-autoloader --no-suggest --no-progress
+  - pecl install yaml
 
 before_deploy:
   - php -d phar.readonly=0 bin/compile