diff --git a/.travis.yml b/.travis.yml
index ec0982a..d63660a 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -6,16 +6,18 @@ matrix:
     fast_finish: true
     include:
         - php: 5.5
-#        - php: 5.6
-#          env: GRAPHQLPHP_VERSION=0.10.*
         - php: 5.6
         - php: 7.0
         - php: 7.1
+        - php: 7.1
+          env: COMPOSER_UPDATE_FLAGS=--prefer-lowest
         - php: 7.2
         - php: hhvm
         - php: nightly
+          env: COMPOSER_UPDATE_FLAGS=--ignore-platform-reqs
     allow_failures:
         - php: nightly
+          env: COMPOSER_UPDATE_FLAGS=--ignore-platform-reqs
 
 branches:
     only:
@@ -27,11 +29,11 @@ cache:
         - $HOME/.composer/cache
 
 before_install:
-    - if [[ "$TRAVIS_PHP_VERSION" != "7.1" && "$TRAVIS_PHP_VERSION" != "hhvm" ]]; then phpenv config-rm xdebug.ini || true; fi
+    - if [[ "$TRAVIS_PHP_VERSION" != "7.1=" && "$TRAVIS_PHP_VERSION" != "hhvm" ]]; then phpenv config-rm xdebug.ini || true; fi
     - composer selfupdate
     - if [ "$GRAPHQLPHP_VERSION" != "" ]; then composer require "webonyx/graphql-php:${GRAPHQLPHP_VERSION}" --dev --no-update; fi;
 
-install: composer update --prefer-dist --no-interaction --optimize-autoloader
+install: composer update --prefer-source --no-interaction --optimize-autoloader ${COMPOSER_UPDATE_FLAGS}
 
 script: ./bin/travis_phpunit
 after_script:
diff --git a/composer.json b/composer.json
index 9ac6880..38c59d8 100644
--- a/composer.json
+++ b/composer.json
@@ -16,16 +16,16 @@
     },
     "require": {
         "php": "^5.4|~7.0",
-        "webonyx/graphql-php": "^0.11.0"
+        "webonyx/graphql-php": "^0.11.2"
     },
     "require-dev": {
         "fabpot/php-cs-fixer": "^1.11",
         "phpunit/phpunit": "^4.1|^5.1",
         "sllh/php-cs-fixer-styleci-bridge": "^1.5",
-        "symfony/expression-language": "^2.7|^3.0",
-        "symfony/filesystem": "^2.7|^3.0",
-        "symfony/process": "^2.7|^3.0",
-        "symfony/yaml": "^2.7|^3.0"
+        "symfony/expression-language": "^3.3",
+        "symfony/filesystem": "^3.3",
+        "symfony/process": "^3.3",
+        "symfony/yaml": "^3.3"
     },
     "autoload": {
         "psr-4": {