diff --git a/htdocs/projet/class/project.class.php b/htdocs/projet/class/project.class.php
index 779666b4b9d..59d24e5eb3d 100644
--- a/htdocs/projet/class/project.class.php
+++ b/htdocs/projet/class/project.class.php
@@ -190,10 +190,10 @@ class Project extends CommonObject
             dol_syslog(get_class($this)."::create error -1 ref null", LOG_ERR);
             return -1;
         }
-        if (! empty($conf->global->PROJECT_THIRDPARTY_REQUIRED) && ! $this->socid > 0)
+        if (! empty($conf->global->PROJECT_THIRDPARTY_REQUIRED) && ! ($this->socid > 0))
         {
             $this->error = 'ErrorFieldsRequired';
-            dol_syslog(get_class($this)."::create error -1 ref null", LOG_ERR);
+            dol_syslog(get_class($this)."::create error -1 thirdparty not defined and option PROJECT_THIRDPARTY_REQUIRED is set", LOG_ERR);
             return -1;
         }