diff --git a/lib/private/Authentication/Token/DefaultToken.php b/lib/private/Authentication/Token/DefaultToken.php
index ad4ece0c46..e2753ba979 100644
--- a/lib/private/Authentication/Token/DefaultToken.php
+++ b/lib/private/Authentication/Token/DefaultToken.php
@@ -158,9 +158,11 @@ class DefaultToken extends Entity implements IToken {
 		return $scope;
 	}
 
-	public function setScope(array $scope = null) {
-		if ($scope !== null) {
+	public function setScope($scope) {
+		if (\is_array($scope)) {
 			parent::setScope(json_encode($scope));
+		} else {
+			parent::setScope((string)$scope);
 		}
 	}
 
diff --git a/lib/private/Authentication/Token/IToken.php b/lib/private/Authentication/Token/IToken.php
index eff525c8d6..b40f55fb6c 100644
--- a/lib/private/Authentication/Token/IToken.php
+++ b/lib/private/Authentication/Token/IToken.php
@@ -94,7 +94,7 @@ interface IToken extends JsonSerializable {
 	 *
 	 * @param array $scope
 	 */
-	public function setScope(array $scope = null);
+	public function setScope($scope);
 
 	public function getName(): string;