diff --git a/lib/private/AllConfig.php b/lib/private/AllConfig.php
index 40a52b16628b3..beb4db625716e 100644
--- a/lib/private/AllConfig.php
+++ b/lib/private/AllConfig.php
@@ -478,22 +478,25 @@ public function getUserValueForUsers($appName, $key, $userIds) {
 	 * @param string $value the value to get the user for
 	 * @return array of user IDs
 	 */
-	public function getUsersForUserValue($appName, $key, $value) {
+	public function getUsersForUserValue($appName, $key, $value = null) {
 		// TODO - FIXME
 		$this->fixDIInit();
 
 		$sql = 'SELECT `userid` FROM `*PREFIX*preferences` ' .
 				'WHERE `appid` = ? AND `configkey` = ? ';
 
-		if ($this->getSystemValue('dbtype', 'sqlite') === 'oci') {
-			//oracle hack: need to explicitly cast CLOB to CHAR for comparison
-			$sql .= 'AND to_char(`configvalue`) = ?';
+		if ($value !== null) {
+			if ($this->getSystemValue('dbtype', 'sqlite') === 'oci') {
+				//oracle hack: need to explicitly cast CLOB to CHAR for comparison
+				$sql .= 'AND to_char(`configvalue`) = ?';
+			} else {
+				$sql .= 'AND `configvalue` = ?';
+			}
+			$result = $this->connection->executeQuery($sql, [$appName, $key, $value]);
 		} else {
-			$sql .= 'AND `configvalue` = ?';
+			$result = $this->connection->executeQuery($sql, [$appName, $key]);
 		}
 
-		$result = $this->connection->executeQuery($sql, [$appName, $key, $value]);
-
 		$userIDs = [];
 		while ($row = $result->fetch()) {
 			$userIDs[] = $row['userid'];
diff --git a/lib/public/IConfig.php b/lib/public/IConfig.php
index 6b396624556ca..20f68dfaaae36 100644
--- a/lib/public/IConfig.php
+++ b/lib/public/IConfig.php
@@ -198,7 +198,7 @@ public function getUserValue($userId, $appName, $key, $default = '');
 	 *
 	 * @param string $appName app to get the value for
 	 * @param string $key the key to get the value for
-	 * @param array $userIds the user IDs to fetch the values for
+	 * @param null|array $userIds the user IDs to fetch the values for, all users with values if null
 	 * @return array Mapped values: userId => value
 	 * @since 8.0.0
 	 */
@@ -245,9 +245,9 @@ public function deleteAppFromAllUsers($appName);
 	 *
 	 * @param string $appName the app to get the user for
 	 * @param string $key the key to get the user for
-	 * @param string $value the value to get the user for
+	 * @param null|string $value the value to get the user for, all users with set key if $value is null
 	 * @return array of user IDs
 	 * @since 8.0.0
 	 */
-	public function getUsersForUserValue($appName, $key, $value);
+	public function getUsersForUserValue($appName, $key, $value = null);
 }