diff --git a/Makefile b/Makefile
index a918118..c255e0a 100644
--- a/Makefile
+++ b/Makefile
@@ -42,7 +42,7 @@ prepare:
 	php $(BUILD_DIR)/fix-some-stuff-in-composer.php
 	composer --working-dir='$(BUILD_DIR)' config platform.php '$(PHP)'
 	composer install --working-dir='$(BUILD_DIR)' --no-scripts --no-plugins --no-dev --no-interaction --optimize-autoloader
-	./vendor/bin/box compile --working-dir='$(BUILD_DIR)'
+	php -d error_reporting='(E_ALL & ~E_DEPRECATED)' ./vendor/bin/box compile --working-dir='$(BUILD_DIR)' -vvv
 	# Copy composer plugin
 	cp '$(BUILD_DIR)/src/Composer/GrumPHPPlugin.php' '$(ROOT_DIR)/src/Composer/GrumPHPPlugin.php'
 	# All good : lets finish up
diff --git a/build/scoper.inc.php b/build/scoper.inc.php
index ff62b9c..4e1335c 100644
--- a/build/scoper.inc.php
+++ b/build/scoper.inc.php
@@ -27,15 +27,22 @@
 );
 
 return [
-    'whitelist' => [
-        'GrumPHP\*',
-        'PhpParser\*',
-        'Composer\*',
-        'Symfony\\Polyfill\\*',
+    'exclude-namespaces' => [
+        'GrumPHP',
+        'PhpParser',
+        'Composer',
+        'Symfony\Polyfill',
     ],
-    'files-whitelist' => [
+    'exclude-files' => [
         ...$polyfillsBootstraps,
         ...$polyfillsStubs
     ],
+    /*
+     * Expose global symbols fixes issues like `trigger_deprecation()` inside Symfony.
+     * These global function gets scoped, but the usage is not replaced.
+     */
+    'expose-global-functions' => true,
+    'expose-global-classes' => true,
+    'expose-global-constants' => true,
     'patchers' => []
 ];
diff --git a/composer.json b/composer.json
index ef720ce..77f971a 100644
--- a/composer.json
+++ b/composer.json
@@ -23,8 +23,7 @@
     "composer-plugin-api": "~2.0"
   },
   "require-dev": {
-    "humbug/box": "^3.12.2",
-    "jetbrains/phpstorm-stubs": "dev-master@dev"
+    "humbug/box": "^3.16"
   },
   "replace": {
     "phpro/grumphp": "self.version"