diff --git a/lib/Db/Bookmark.php b/lib/Db/Bookmark.php
index 0c85f34..76ac1d0 100644
--- a/lib/Db/Bookmark.php
+++ b/lib/Db/Bookmark.php
@@ -26,8 +26,8 @@ class Bookmark extends ReaderEntity implements \JsonSerializable {
 			'fileId' => $this->getFileId(),
 			'type' => $this->getType(),
 			'name' => $this->getName(),
-			'value' => static::conditional_json_decode($this->getValue()),
-			'content' => static::conditional_json_decode($this->getContent()),
+			'value' => $this->conditional_json_decode($this->getValue()),
+			'content' => $this->conditional_json_decode($this->getContent()),
 			'lastModified' => $this->getLastModified()
 		];
 	}
@@ -48,6 +48,7 @@ class Bookmark extends ReaderEntity implements \JsonSerializable {
 
 	public function setUserId(string $userId): void {
 		$this->userId = $userId;
+		$this->markFieldUpdated('userId');
 	}
 
 	public function getFileId(): int {
@@ -56,6 +57,7 @@ class Bookmark extends ReaderEntity implements \JsonSerializable {
 
 	public function setFileId(int $fileId): void {
 		$this->fileId = $fileId;
+		$this->markFieldUpdated('fileId');
 	}
 
 	public function getType(): string {
@@ -64,6 +66,7 @@ class Bookmark extends ReaderEntity implements \JsonSerializable {
 
 	public function setType(string $type): void {
 		$this->type = $type;
+		$this->markFieldUpdated('type');
 	}
 
 	public function getName(): string {
@@ -72,6 +75,7 @@ class Bookmark extends ReaderEntity implements \JsonSerializable {
 
 	public function setName(string $name): void {
 		$this->name = $name;
+		$this->markFieldUpdated('name');
 	}
 
 	public function getValue(): string {
@@ -80,6 +84,7 @@ class Bookmark extends ReaderEntity implements \JsonSerializable {
 
 	public function setValue(string $value): void {
 		$this->value = $value;
+		$this->markFieldUpdated('value');
 	}
 
 	public function getContent(): string {
@@ -88,5 +93,6 @@ class Bookmark extends ReaderEntity implements \JsonSerializable {
 
 	public function setContent(string $content): void {
 		$this->content = $content;
+		$this->markFieldUpdated('content');
 	}
 }
diff --git a/lib/Db/Preference.php b/lib/Db/Preference.php
index d19520c..0f11de3 100644
--- a/lib/Db/Preference.php
+++ b/lib/Db/Preference.php
@@ -42,6 +42,7 @@ class Preference extends ReaderEntity implements \JsonSerializable {
 
 	public function setUserId(string $userId): void {
 		$this->userId = $userId;
+		$this->markFieldUpdated('userId');
 	}
 
 	public function getScope(): string {
@@ -50,6 +51,7 @@ class Preference extends ReaderEntity implements \JsonSerializable {
 
 	public function setScope(string $scope): void {
 		$this->scope = $scope;
+		$this->markFieldUpdated('scope');
 	}
 
 	public function getFileId(): int {
@@ -58,6 +60,7 @@ class Preference extends ReaderEntity implements \JsonSerializable {
 
 	public function setFileId(int $fileId): void {
 		$this->fileId = $fileId;
+		$this->markFieldUpdated('fileId');
 	}
 
 	public function getName(): string {
@@ -66,6 +69,7 @@ class Preference extends ReaderEntity implements \JsonSerializable {
 
 	public function setName(string $name): void {
 		$this->name = $name;
+		$this->markFieldUpdated('name');
 	}
 
 	public function getValue(): string {
@@ -74,5 +78,6 @@ class Preference extends ReaderEntity implements \JsonSerializable {
 
 	public function setValue(string $value): void {
 		$this->value = $value;
+		$this->markFieldUpdated('value');
 	}
 }
diff --git a/lib/Db/ReaderEntity.php b/lib/Db/ReaderEntity.php
index f9bbbc8..66eb48a 100644
--- a/lib/Db/ReaderEntity.php
+++ b/lib/Db/ReaderEntity.php
@@ -24,7 +24,7 @@ abstract class ReaderEntity extends Entity {
 	 *
 	 * @return string|array
 	 */
-	public static function conditional_json_decode(string $el): mixed {
+	public function conditional_json_decode(string $el): mixed {
 		/** @var array $result */
 		$result = json_decode($el);
 		if (json_last_error() === JSON_ERROR_NONE) {
@@ -40,6 +40,7 @@ abstract class ReaderEntity extends Entity {
 
 	public function setLastModified(int $lastModified): void {
 		$this->lastModified = $lastModified;
+		$this->markFieldUpdated('lastModified');
 	}
 
 	/**
diff --git a/lib/Hooks.php b/lib/Hooks.php
index 3864fb3..aa41432 100644
--- a/lib/Hooks.php
+++ b/lib/Hooks.php
@@ -18,7 +18,7 @@ use OCP\Server;
 
 class Hooks {
 
-	public static function announce_settings(array $settings): void {
+	public function announce_settings(array $settings): void {
 		// Nextcloud encodes this as JSON, Owncloud does not (yet) (#75)
 		// TODO: remove this when Owncloud starts encoding oc_appconfig as JSON just like it already encodes most other properties
 		$user = Server::get(IUserSession::class)->getUser();
@@ -39,7 +39,7 @@ class Hooks {
 		}
 	}
 
-	protected static function deleteFile(IDBConnection $connection, int $fileId): void {
+	protected function deleteFile(IDBConnection $connection, int $fileId): void {
 		$queryBuilder = $connection->getQueryBuilder();
 		$queryBuilder->delete('reader_bookmarks')->where('file_id = file_id')->setParameter('file_id', $fileId);
 		$queryBuilder->executeStatement();
@@ -49,7 +49,7 @@ class Hooks {
 		$queryBuilder->executeStatement();
 	}
 
-	protected static function deleteUser(IDBConnection $connection, string $userId): void {
+	protected function deleteUser(IDBConnection $connection, string $userId): void {
 		$queryBuilder = $connection->getQueryBuilder();
 		$queryBuilder->delete('reader_bookmarks')->where('user_id = user_id')->setParameter('user_id', $userId);
 		$queryBuilder->executeStatement();
@@ -59,7 +59,7 @@ class Hooks {
 		$queryBuilder->executeStatement();
 	}
 
-	private static function isJson(mixed $string): bool {
+	private function isJson(mixed $string): bool {
 		return is_string($string) && is_array(json_decode($string, true)) && (json_last_error() == JSON_ERROR_NONE) ? true : false;
 	}
 }