-enablePassThrough false

@link php-webdriver/php-webdriver#468

.travis.yml

@@ -31,7 +31,7 @@ before_script:
   - sleep 3 # give xvfb some time to start
   - if [ "$BROWSER_NAME" = "firefox" ]; then wget -q -t 3 https://github.com/mozilla/geckodriver/releases/download/v$GECKODRIVER_VERSION/geckodriver-v$GECKODRIVER_VERSION-linux64.tar.gz; mkdir geckodriver; tar -xvf geckodriver-v$GECKODRIVER_VERSION-linux64.tar.gz -C geckodriver; export PATH=$PATH:$PWD/geckodriver; fi
   - if [ ! -f jar/$JAR_FILE ]; then wget -q -t 3 -P jar http://selenium-release.storage.googleapis.com/$SELENIUM_SERVER_VERSION/$JAR_FILE; fi
-  - java -jar jar/$JAR_FILE &
+  - java -jar jar/$JAR_FILE -enablePassThrough false &
   - until $(echo | nc localhost 4444); do sleep 1; echo Waiting for Selenium server on port 4444...; done; echo "Selenium server started"
   - php -S 127.0.0.1:8000 -t tests/ci/web/ &
   - until $(echo | nc localhost 8000); do sleep 1; echo waiting for PHP server on port 8000...; done; echo "PHP server started"