diff --git a/src/Tgstation.Server.Host/Components/Interop/Topic/TopicResponse.cs b/src/Tgstation.Server.Host/Components/Interop/Topic/TopicResponse.cs
index 3b936b514e..12db6f3ef1 100644
--- a/src/Tgstation.Server.Host/Components/Interop/Topic/TopicResponse.cs
+++ b/src/Tgstation.Server.Host/Components/Interop/Topic/TopicResponse.cs
@@ -2,8 +2,6 @@
 
 using Tgstation.Server.Host.Components.Chat.Commands;
 
-#nullable disable
-
 namespace Tgstation.Server.Host.Components.Interop.Topic
 {
 	/// <summary>
@@ -14,29 +12,29 @@ namespace Tgstation.Server.Host.Components.Interop.Topic
 		/// <summary>
 		/// The text to reply with as the result of a <see cref="TopicCommandType.ChatCommand"/> request, if any. Deprecated circa Interop 5.4.0.
 		/// </summary>
-		public string CommandResponseMessage { get; set; }
+		public string? CommandResponseMessage { get; set; }
 
 		/// <summary>
 		/// The <see cref="ChatMessage"/> response from a <see cref="ChatCommand"/>. Added in Interop 5.4.0.
 		/// </summary>
-		public ChatMessage CommandResponse { get; set; }
+		public ChatMessage? CommandResponse { get; set; }
 
 		/// <summary>
 		/// The <see cref="ChatMessage"/>s to send as the result of a <see cref="TopicCommandType.EventNotification"/> request, if any.
 		/// </summary>
-		public ICollection<ChatMessage> ChatResponses { get; set; }
+		public ICollection<ChatMessage>? ChatResponses { get; set; }
 
 		/// <summary>
 		/// The DMAPI <see cref="CustomCommand"/>s for <see cref="TopicCommandType.ServerRestarted"/> requests.
 		/// </summary>
-		public ICollection<CustomCommand> CustomCommands { get; set; }
+		public ICollection<CustomCommand>? CustomCommands { get; set; }
 
 		/// <summary>
 		/// The <see cref="ChunkData"/> for a partial response.
 		/// </summary>
-		public ChunkData Chunk { get; set; }
+		public ChunkData? Chunk { get; set; }
 
 		/// <inheritdoc />
-		public IReadOnlyCollection<uint> MissingChunks { get; set; }
+		public IReadOnlyCollection<uint>? MissingChunks { get; set; }
 	}
 }