diff --git a/.travis.yml b/.travis.yml
index b55c9b9..90e8fde 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -19,7 +19,7 @@ before_install:
     - travis_retry composer self-update
 
 install:
-    - travis_retry composer update ${COMPOSER_FLAGS} --prefer-source --no-interaction
+    - travis_retry composer update --no-interaction
 
 script:
     - composer test-ci
\ No newline at end of file