diff --git a/test/phpunit/SocieteTest.php b/test/phpunit/SocieteTest.php
index 9a4f58540e9..7773ddcaf22 100755
--- a/test/phpunit/SocieteTest.php
+++ b/test/phpunit/SocieteTest.php
@@ -401,7 +401,7 @@ class SocieteTest extends PHPUnit\Framework\TestCase
 		$result=$localobject->getOutstandingBills();
 
 		print __METHOD__." id=".$id." result=".var_export($result, true)."\n";
-		$this->assertLessThan($result, 0);
+		$this->assertTrue(array_key_exists('opened', $result), 'Result of getOutstandingBills failed');
 
 		return $id;
 	}