diff --git a/.travis.yml b/.travis.yml
index b419b318..e9e3503d 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -25,4 +25,4 @@ install:
     - composer config extra.symfony.allow-contrib true
 
 script:
-    - composer req --ignore-platform-reqs "${PACKAGES}"
+    - composer req --ignore-platform-reqs $(echo $PACKAGES)