diff --git a/.travis.yml b/.travis.yml
index 2f5018d..0576d02 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -14,6 +14,6 @@ env:
 
 before_script:
     - bash bin/install-wp-tests.sh wordpress_test root '' localhost $WP_VERSION
-    - fgrep wp_version $WP_TESTS_DIR/wp-includes/version.php
+    - fgrep wp_version ${WP_TESTS_DIR-/tmp/wordpress-tests-lib}/wp-includes/version.php
 
 script: phpunit