diff --git a/src/Avalonia.Dialogs/ManagedFileChooserViewModel.cs b/src/Avalonia.Dialogs/ManagedFileChooserViewModel.cs
index a6847939d7..03e05e7a75 100644
--- a/src/Avalonia.Dialogs/ManagedFileChooserViewModel.cs
+++ b/src/Avalonia.Dialogs/ManagedFileChooserViewModel.cs
@@ -255,7 +255,7 @@ namespace Avalonia.Dialogs
                     {
                         if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
                         {
-                            infos = infos.Where(i => (i.Attributes & (FileAttributes.Hidden | FileAttributes.System)) != 0);
+                            infos = infos.Where(i => (i.Attributes & (FileAttributes.Hidden | FileAttributes.System)) == 0);
                         }
                         else
                         {
diff --git a/src/Windows/Avalonia.Win32/WindowsMountedVolumeInfoListener.cs b/src/Windows/Avalonia.Win32/WindowsMountedVolumeInfoListener.cs
index 3e2941814f..102e027584 100644
--- a/src/Windows/Avalonia.Win32/WindowsMountedVolumeInfoListener.cs
+++ b/src/Windows/Avalonia.Win32/WindowsMountedVolumeInfoListener.cs
@@ -11,7 +11,7 @@ namespace Avalonia.Win32
     internal class WindowsMountedVolumeInfoListener : IDisposable
     {
         private readonly CompositeDisposable _disposables;
-        private readonly ObservableCollection<MountedVolumeInfo> _targetObs;
+        private readonly ObservableCollection<MountedVolumeInfo> _targetObs = new ObservableCollection<MountedVolumeInfo>();
         private bool _beenDisposed = false;
         private ObservableCollection<MountedVolumeInfo> mountedDrives;