diff --git a/htdocs/core/class/extrafields.class.php b/htdocs/core/class/extrafields.class.php
index 3bbb40737e0..fd6e9aa6efb 100644
--- a/htdocs/core/class/extrafields.class.php
+++ b/htdocs/core/class/extrafields.class.php
@@ -726,6 +726,8 @@ class ExtraFields
 
 			if (is_array($param) && count($param) > 0) {
 				$params = serialize($param);
+			} elseif (is_array($param)) {
+				$params = '';
 			} elseif (strlen($param) > 0) {
 				$params = trim($param);
 			} else {