diff --git a/application/cmdbabstract.class.inc.php b/application/cmdbabstract.class.inc.php
index db70affe93..6b56b279ff 100644
--- a/application/cmdbabstract.class.inc.php
+++ b/application/cmdbabstract.class.inc.php
@@ -4263,9 +4263,30 @@ protected function PrepareValueFromPostedForm($sFormPrefix, $sAttCode, $sClass =
 			case 'Set':
 			case 'TagSet':
 				$sTagSetJson = utils::ReadPostedParam("attr_{$sFormPrefix}{$sAttCode}", null, 'raw_data');
-			if ($sTagSetJson !== null) { // bulk modify, direct linked set not handled
-				$value = json_decode($sTagSetJson, true);
-			}
+				if ($sTagSetJson !== null) { // bulk modify, direct linked set not handled
+					$value = json_decode($sTagSetJson, true);
+					if ($this->IsNew()) {
+						if ($value['orig_value'] != '' ) {
+							foreach ($value['orig_value'] as $val) {
+								if (!in_array($val, $value['removed'])) {
+									$value['added'][] = $val;
+								}
+							}
+						}
+					} else {
+						$acurrentValues = $this->Get($sAttCode)->GetValues();
+						foreach ($value['orig_value'] as $val) {
+							if ( !in_array($val, $acurrentValues) && !in_array($val, $value['removed'])  && !in_array($val, $value['added'])  ) {
+								$value['added'][] = $val;
+							}
+						}
+						foreach ($acurrentValues as $val) {
+							if ( !in_array($val, $value['orig_value']) && !in_array($val, $value['removed'])  && !in_array($val, $value['added'])  ) {
+								$value['removed'][] = $val;
+							}
+						}
+					}
+				}
 				break;
 
 			default: