diff --git a/src/Symfony/Bridge/PhpUnit/bin/simple-phpunit b/src/Symfony/Bridge/PhpUnit/bin/simple-phpunit
index 3043daababc1..92d4d6994af9 100755
--- a/src/Symfony/Bridge/PhpUnit/bin/simple-phpunit
+++ b/src/Symfony/Bridge/PhpUnit/bin/simple-phpunit
@@ -65,11 +65,13 @@ foreach ($defaultEnvs as $envName => $envValue) {
     }
 }
 
-$COMPOSER = file_exists($COMPOSER = $oldPwd.'/composer.phar')
-    || ($COMPOSER = rtrim('\\' === DIRECTORY_SEPARATOR ? preg_replace('/[\r\n].*/', '', `where.exe composer.phar`) : `which composer.phar 2> /dev/null`))
-    || ($COMPOSER = rtrim('\\' === DIRECTORY_SEPARATOR ? preg_replace('/[\r\n].*/', '', `where.exe composer`) : `which composer 2> /dev/null`))
-    ? (file_get_contents($COMPOSER, false, null, 0, 18) === '#!/usr/bin/env php' ? $PHP : '').' '.escapeshellarg($COMPOSER) // detect shell wrappers by looking at the shebang
-    : 'composer';
+if (false === $COMPOSER = \getenv('COMPOSER_BINARY')) {
+    $COMPOSER = file_exists($COMPOSER = $oldPwd.'/composer.phar')
+        || ($COMPOSER = rtrim('\\' === DIRECTORY_SEPARATOR ? preg_replace('/[\r\n].*/', '', `where.exe composer.phar`) : `which composer.phar 2> /dev/null`))
+        || ($COMPOSER = rtrim('\\' === DIRECTORY_SEPARATOR ? preg_replace('/[\r\n].*/', '', `where.exe composer`) : `which composer 2> /dev/null`))
+        ? (file_get_contents($COMPOSER, false, null, 0, 18) === '#!/usr/bin/env php' ? $PHP : '').' '.escapeshellarg($COMPOSER) // detect shell wrappers by looking at the shebang
+        : 'composer';
+}
 
 if (false === $SYMFONY_PHPUNIT_REMOVE = getenv('SYMFONY_PHPUNIT_REMOVE')) {
     $SYMFONY_PHPUNIT_REMOVE = 'phpspec/prophecy symfony/yaml';