diff --git a/app/src/main/java/org/schabi/newpipe/util/FilePickerActivityHelper.java b/app/src/main/java/org/schabi/newpipe/util/FilePickerActivityHelper.java
index 82e74adec..d56913648 100644
--- a/app/src/main/java/org/schabi/newpipe/util/FilePickerActivityHelper.java
+++ b/app/src/main/java/org/schabi/newpipe/util/FilePickerActivityHelper.java
@@ -116,7 +116,7 @@ public class FilePickerActivityHelper extends com.nononsenseapps.filepicker.File
         }
 
         @Override
-        protected boolean isItemVisible(File file) {
+        protected boolean isItemVisible(@NonNull File file) {
             if (file.isDirectory() && file.isHidden()) return true;
             return super.isItemVisible(file);
         }