diff --git a/src/Tgstation.Server.Host/Components/Interop/Topic/TopicParameters.cs b/src/Tgstation.Server.Host/Components/Interop/Topic/TopicParameters.cs
index 8674e0679d..f84a404289 100644
--- a/src/Tgstation.Server.Host/Components/Interop/Topic/TopicParameters.cs
+++ b/src/Tgstation.Server.Host/Components/Interop/Topic/TopicParameters.cs
@@ -4,8 +4,6 @@ using Newtonsoft.Json;
 
 using Tgstation.Server.Host.Components.Session;
 
-#nullable disable
-
 namespace Tgstation.Server.Host.Components.Interop.Topic
 {
 	/// <summary>
@@ -22,12 +20,12 @@ namespace Tgstation.Server.Host.Components.Interop.Topic
 		/// <summary>
 		/// The <see cref="Topic.ChatCommand"/> for <see cref="TopicCommandType.ChatCommand"/> requests.
 		/// </summary>
-		public ChatCommand ChatCommand { get; }
+		public ChatCommand? ChatCommand { get; }
 
 		/// <summary>
 		/// The <see cref="Topic.EventNotification"/> for <see cref="TopicCommandType.EventNotification"/> requests.
 		/// </summary>
-		public EventNotification EventNotification { get; }
+		public EventNotification? EventNotification { get; }
 
 		/// <summary>
 		/// The new port for <see cref="TopicCommandType.ChangePort"/> or <see cref="TopicCommandType.ServerPortUpdate"/> requests.
@@ -42,27 +40,27 @@ namespace Tgstation.Server.Host.Components.Interop.Topic
 		/// <summary>
 		/// The new <see cref="Api.Models.NamedEntity.Name"/> for <see cref="TopicCommandType.InstanceRenamed"/> requests.
 		/// </summary>
-		public string NewInstanceName { get; }
+		public string? NewInstanceName { get; }
 
 		/// <summary>
 		/// The message to broadcast for <see cref="TopicCommandType.Broadcast"/> requests.
 		/// </summary>
-		public string BroadcastMessage { get; }
+		public string? BroadcastMessage { get; }
 
 		/// <summary>
 		/// The <see cref="Interop.ChatUpdate"/> for <see cref="TopicCommandType.ChatChannelsUpdate"/> requests.
 		/// </summary>
-		public ChatUpdate ChatUpdate { get; }
+		public ChatUpdate? ChatUpdate { get; }
 
 		/// <summary>
 		/// The new server <see cref="Version"/> after a reattach.
 		/// </summary>
-		public Version NewServerVersion { get; }
+		public Version? NewServerVersion { get; }
 
 		/// <summary>
 		/// The <see cref="ChunkData"/> for a partial request.
 		/// </summary>
-		public ChunkData Chunk { get; }
+		public ChunkData? Chunk { get; }
 
 		/// <summary>
 		/// Whether or not the <see cref="TopicParameters"/> constitute a priority request.