diff --git a/htdocs/core/lib/functions.lib.php b/htdocs/core/lib/functions.lib.php
index 87ee457fa7d..a378cd2c01e 100644
--- a/htdocs/core/lib/functions.lib.php
+++ b/htdocs/core/lib/functions.lib.php
@@ -52,6 +52,7 @@ function getStaticMember($class, $member)
 	}
 
 	dol_print_error('','Try to get a static member "'.$member.'" in class "'.$class.'" that does not exists or is not static.');
+	return null;
 }