diff --git a/datamodels/2.x/itop-request-mgmt/datamodel.itop-request-mgmt.xml b/datamodels/2.x/itop-request-mgmt/datamodel.itop-request-mgmt.xml
index 263fadfec1..91d7ee388a 100755
--- a/datamodels/2.x/itop-request-mgmt/datamodel.itop-request-mgmt.xml
+++ b/datamodels/2.x/itop-request-mgmt/datamodel.itop-request-mgmt.xml
@@ -306,11 +306,8 @@
           <is_null_allowed>true</is_null_allowed>
         </field>
         <field id="servicesubcategory_id" xsi:type="AttributeExternalKey">
-          <filter><![CDATA[SELECT ServiceSubcategory WHERE service_id = :this->service_id AND (ISNULL(:this->request_type) OR request_type = :this->request_type) AND status != 'obsolete']]></filter>
-          <dependencies>
-            <attribute id="service_id"/>
-            <attribute id="request_type"/>
-          </dependencies>
+          <filter><![CDATA[SELECT ServiceSubcategory WHERE service_id = :this->service_id AND status != 'obsolete']]></filter>
+          <dependencies/>
           <sql>servicesubcategory_id</sql>
           <target_class>ServiceSubcategory</target_class>
           <is_null_allowed>true</is_null_allowed>
@@ -1334,19 +1331,21 @@
 		// Compute the priority of the ticket
 		$this->Set('priority', $this->ComputePriority());
 
-		// Compute the request_type if not already defined (by the user)
-		$sType = $this->Get('request_type');
-        if (is_null($sType) || ($sType === ''))
+		return parent::ComputeValues();
+	}]]></code>
+        </method>
+        <method id="EvtComputeRequestType">
+          <static>false</static>
+          <access>public</access>
+          <type>EventListener</type>
+          <code><![CDATA[	public function EvtComputeRequestType(?Combodo\iTop\Service\Events\EventData $oEventData = null)
+	{
+		$iSvcSubcat = $this->Get('servicesubcategory_id');
+		if ($iSvcSubcat != 0)
 		{
-			$iSvcSubcat = $this->Get('servicesubcategory_id');
-			if ($iSvcSubcat != 0)
-			{
-				$oSvcSubcat = MetaModel::GetObject(ServiceSubcategory::class, $iSvcSubcat, true, true);
-				$this->Set('request_type', $oSvcSubcat->Get('request_type'));
-			}
+			$oSvcSubcat = MetaModel::GetObject(ServiceSubcategory::class, $iSvcSubcat, true, true);
+			$this->Set('request_type', $oSvcSubcat->Get('request_type'));
 		}
-
-		return parent::ComputeValues();
 	}]]></code>
         </method>
         <method id="DisplayBareRelations">
@@ -1528,6 +1527,13 @@
 	}]]></code>
         </method>
       </methods>
+      <event_listeners>
+        <event_listener id="EVENT_DB_BEFORE_WRITE">
+          <event>EVENT_DB_BEFORE_WRITE</event>
+          <callback>EvtComputeRequestType</callback>
+          <rank>0</rank>
+        </event_listener>
+      </event_listeners>
       <presentation>
         <details>
           <items>