diff --git a/dev/examples/zapier/README.md b/dev/examples/zapier/README.md
index ff101919284..453a5224993 100644
--- a/dev/examples/zapier/README.md
+++ b/dev/examples/zapier/README.md
@@ -3,9 +3,9 @@
 
 ## ENABLE MODULE ZAPIER ON DOLIBARR
 
-This should also enable the module API (required for authentication by Zapier service).
+This should also enable the module API (required for authentication by Zapier service and to execute action in Dolibarr by Zapier).
 
-Create the Dolibarr login that will be used by Zapier to call APIs.
+Create the Dolibarr login that will be used by Zapier to call APIs. Give the login the permissions on the action you plan to automate.
 
 
 ## CREATE A ZAPIER DEVELOPPER ACCOUNT
diff --git a/htdocs/core/class/commonobject.class.php b/htdocs/core/class/commonobject.class.php
index 76d6a1f1bd1..49483224a8a 100644
--- a/htdocs/core/class/commonobject.class.php
+++ b/htdocs/core/class/commonobject.class.php
@@ -7538,9 +7538,12 @@ abstract class CommonObject
 				if ($field == 'entity' && is_null($this->{$field})) $queryarray[$field] = $conf->entity;
 				else {
 					// $this->{$field} may be null, '', 0, '0', 123, '123'
-					if ($this->{$field} != '' || !empty($info['notnull'])) {
-						if ($this->isInt($info)) $queryarray[$field] = (int) $this->{$field};	// If '0', it may be set to null later if $info['notnull'] == -1
-						if ($this->isFloat($info)) $queryarray[$field] = (double) $this->{$field};	// If '0', it may be set to null later if $info['notnull'] == -1
+					if ((isset($this->{$field}) && $this->{$field} != '') || !empty($info['notnull'])) {
+						if ($this->isInt($info)) {
+							$queryarray[$field] = (int) $this->{$field};	// If '0', it may be set to null later if $info['notnull'] == -1
+						} elseif ($this->isFloat($info)) {
+							$queryarray[$field] = (double) $this->{$field};	// If '0', it may be set to null later if $info['notnull'] == -1
+						}
 					} else $queryarray[$field] = null;
 				}
 			} else {