diff --git a/phpunit b/phpunit
index 7e1f519a26..0d91ad43f9 100755
--- a/phpunit
+++ b/phpunit
@@ -3,9 +3,14 @@
 
 error_reporting(-1);
 
-$PHPUNIT_VERSION = 4.8;
+$PHPUNIT_VERSION = '4.8';
 $PHPUNIT_DIR = __DIR__.'/.phpunit';
 
+// PHPUnit 4.8 does not support PHP 7, while 5.0 requires PHP 5.6+
+if (PHP_VERSION_ID >= 70000) {
+    $PHPUNIT_DIR = '5.0';
+}
+
 if (!file_exists("$PHPUNIT_DIR/phpunit-$PHPUNIT_VERSION/phpunit")) {
     // Build a standalone phpunit without symfony/yaml