diff --git a/.travis.yml b/.travis.yml
index 70a3370cd7..b492094268 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -56,13 +56,13 @@ after_script:
 
 matrix:
   allow_failures:
-    - php: 5.6
+    - php: "5.6"
       env: PHPUNIT_ARGS="--group selenium" SELENIUM="yes" CI_MODE="selenium"
   fast_finish: true
   include:
-    - php: 5.6
+    - php: "5.6"
       env: PHPUNIT_ARGS="--group selenium" SELENIUM="yes" CI_MODE="selenium"
-    - php: 7.0
+    - php: "7.0"
       env: CI_MODE="release"
 cache:
   directories: