1 files changed, 2 insertions, 2 deletions
diff --git a/lib/private/files/node/root.php b/lib/private/files/node/root.php
index e47f98b0f27..7ffb3674a8f 100644
--- a/lib/private/files/node/root.php
+++ b/lib/private/files/node/root.php
@@ -94,7 +94,7 @@ class Root extends Folder implements IRootFolder {
 	 * @param string $method
 	 * @param callable $callback
 	 */
-	public function listen($scope, $method, $callback) {
+	public function listen($scope, $method, callable $callback) {
 		$this->emitter->listen($scope, $method, $callback);
 	}
 
@@ -103,7 +103,7 @@ class Root extends Folder implements IRootFolder {
 	 * @param string $method optional
 	 * @param callable $callback optional
 	 */
-	public function removeListener($scope = null, $method = null, $callback = null) {
+	public function removeListener($scope = null, $method = null, callable $callback = null) {
 		$this->emitter->removeListener($scope, $method, $callback);
 	}