diff --git a/src/Lidarr.Api.V1/RootFolders/RootFolderResource.cs b/src/Lidarr.Api.V1/RootFolders/RootFolderResource.cs
index 6684ce3dd..c9ac64dd4 100644
--- a/src/Lidarr.Api.V1/RootFolders/RootFolderResource.cs
+++ b/src/Lidarr.Api.V1/RootFolders/RootFolderResource.cs
@@ -67,7 +67,7 @@ namespace Lidarr.Api.V1.RootFolders
                 DefaultQualityProfileId = resource.DefaultQualityProfileId,
                 DefaultMonitorOption = resource.DefaultMonitorOption,
                 DefaultNewItemMonitorOption = resource.DefaultNewItemMonitorOption,
-                DefaultTags = resource.DefaultTags,
+                DefaultTags = resource.DefaultTags ?? new HashSet<int>()
             };
         }
 
diff --git a/src/NzbDrone.Core/RootFolders/RootFolder.cs b/src/NzbDrone.Core/RootFolders/RootFolder.cs
index e26704c82..138bdf070 100644
--- a/src/NzbDrone.Core/RootFolders/RootFolder.cs
+++ b/src/NzbDrone.Core/RootFolders/RootFolder.cs
@@ -12,7 +12,7 @@ namespace NzbDrone.Core.RootFolders
         public int DefaultQualityProfileId { get; set; }
         public MonitorTypes DefaultMonitorOption { get; set; }
         public NewItemMonitorTypes DefaultNewItemMonitorOption { get; set; }
-        public HashSet<int> DefaultTags { get; set; }
+        public HashSet<int> DefaultTags { get; set; } = new ();
 
         public bool Accessible { get; set; }
         public long? FreeSpace { get; set; }