diff --git a/.travis.yml b/.travis.yml
index 6422e33a7e9..1469894dfc3 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -95,13 +95,13 @@ notifications:
 
 install:
 - |
-  echo "Updating Composer"
-  rm $TRAVIS_BUILD_DIR/composer.json
-  rm $TRAVIS_BUILD_DIR/composer.lock
+  echo "Updating Composer (version 2.5 is bugged and generate phpunit error Exception: Serialization of 'Closure' is not allowed)"
+  #rm $TRAVIS_BUILD_DIR/composer.json
+  #rm $TRAVIS_BUILD_DIR/composer.lock
   composer -V
-  composer self-update
-  composer -n init
-  composer -n config vendor-dir htdocs/includes
+  composer self-update 2.4.4
+  #composer -n init
+  #composer -n config vendor-dir htdocs/includes
   composer -n config -g vendor-dir htdocs/includes
   echo
 
diff --git a/test/phpunit/AdminLibTest.php b/test/phpunit/AdminLibTest.php
index 6649aa19798..4df1a6933e1 100644
--- a/test/phpunit/AdminLibTest.php
+++ b/test/phpunit/AdminLibTest.php
@@ -46,6 +46,7 @@ $conf->global->MAIN_DISABLE_ALL_MAILS=1;
  */
 class AdminLibTest extends PHPUnit\Framework\TestCase
 {
+	protected $backupGlobalsBlacklist = array('conf', 'user', 'langs', 'db');
 	protected $savconf;
 	protected $savuser;
 	protected $savlangs;
@@ -69,6 +70,7 @@ class AdminLibTest extends PHPUnit\Framework\TestCase
 		$this->savdb=$db;
 
 		print __METHOD__." db->type=".$db->type." user->id=".$user->id;
+
 		//print " - db ".$db->db;
 		print "\n";
 	}
diff --git a/test/phpunit/phpunittest.xml b/test/phpunit/phpunittest.xml
index 84b31a8dd3b..8157d3f3e7a 100644
--- a/test/phpunit/phpunittest.xml
+++ b/test/phpunit/phpunittest.xml
@@ -1,8 +1,8 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <!DOCTYPE phpunit SYSTEM "phpunit.dtd" >
 <phpunit
-	backupGlobals="true"
-	backupStaticAttributes="false"
+	backupGlobals="false"
+	backupStaticAttributes="true"
 	convertErrorsToExceptions="true"
 	convertNoticesToExceptions="true"
 	convertWarningsToExceptions="true"