diff --git a/apps/systemtags/lib/Activity/Provider.php b/apps/systemtags/lib/Activity/Provider.php
index c979f8143a8ea..f9f15f558303f 100644
--- a/apps/systemtags/lib/Activity/Provider.php
+++ b/apps/systemtags/lib/Activity/Provider.php
@@ -286,7 +286,7 @@ protected function getSystemTagParameter($parameter) {
 		if ($tagData === null) {
 			[$name, $status] = explode('|||', substr($parameter, 3, -3));
 			$tagData = [
-				'id' => '0',// No way to recover the ID
+				'id' => '0', // No way to recover the ID
 				'name' => $name,
 				'assignable' => $status === 'assignable',
 				'visible' => $status !== 'invisible',
diff --git a/lib/private/SystemTag/SystemTagObjectMapper.php b/lib/private/SystemTag/SystemTagObjectMapper.php
index 3881336bf3780..1fa5975dafb16 100644
--- a/lib/private/SystemTag/SystemTagObjectMapper.php
+++ b/lib/private/SystemTag/SystemTagObjectMapper.php
@@ -287,6 +287,7 @@ public function setObjectIdsForTag(string $tagId, string $objectType, array $obj
 		$currentObjectIds = $this->getObjectIdsForTags($tagId, $objectType);
 		$removedObjectIds = array_diff($currentObjectIds, $objectIds);
 		$addedObjectIds = array_diff($objectIds, $currentObjectIds);
+
 		$this->connection->beginTransaction();
 		$query = $this->connection->getQueryBuilder();
 		$query->delete(self::RELATION_TABLE)
@@ -324,6 +325,8 @@ public function setObjectIdsForTag(string $tagId, string $objectType, array $obj
 
 		$this->updateEtagForTags([$tagId]);
 		$this->connection->commit();
+
+		// Dispatch assign events for new object ids
 		foreach ($addedObjectIds as $objectId) {
 			$this->dispatcher->dispatch(MapperEvent::EVENT_ASSIGN, new MapperEvent(
 				MapperEvent::EVENT_ASSIGN,
@@ -332,6 +335,16 @@ public function setObjectIdsForTag(string $tagId, string $objectType, array $obj
 				[(int)$tagId]
 			));
 		}
+
+		// Dispatch unassign events for removed object ids
+		foreach ($removedObjectIds as $objectId) {
+			$this->dispatcher->dispatch(MapperEvent::EVENT_UNASSIGN, new MapperEvent(
+				MapperEvent::EVENT_UNASSIGN,
+				$objectType,
+				(string)$objectId,
+				[(int)$tagId]
+			));
+		}
 	}
 
 	/**