diff --git a/.travis.yml b/.travis.yml
index b976561..d1ba971 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -5,6 +5,11 @@ php:
   - 7.2
   - 7.3
 
+env:
+  matrix:
+    - COMPOSER_FLAGS="--prefer-lowest"
+    - COMPOSER_FLAGS=""
+
 before_script:
   - composer install --dev --prefer-source --no-interaction