diff --git a/src/Tgstation.Server.Host/Components/Engine/DelegatingEngineInstaller.cs b/src/Tgstation.Server.Host/Components/Engine/DelegatingEngineInstaller.cs
index c7c5363a95..1157dff565 100644
--- a/src/Tgstation.Server.Host/Components/Engine/DelegatingEngineInstaller.cs
+++ b/src/Tgstation.Server.Host/Components/Engine/DelegatingEngineInstaller.cs
@@ -1,5 +1,5 @@
 using System;
-using System.Collections.Generic;
+using System.Collections.Frozen;
 using System.Linq;
 using System.Threading;
 using System.Threading.Tasks;
@@ -15,15 +15,15 @@ namespace Tgstation.Server.Host.Components.Engine
 	sealed class DelegatingEngineInstaller : IEngineInstaller
 	{
 		/// <summary>
-		/// The <see cref="IReadOnlyDictionary{TKey, TValue}"/> mapping <see cref="EngineType"/>s to their appropriate <see cref="IEngineInstaller"/>.
+		/// The <see cref="FrozenDictionary{TKey, TValue}"/> mapping <see cref="EngineType"/>s to their appropriate <see cref="IEngineInstaller"/>.
 		/// </summary>
-		readonly IReadOnlyDictionary<EngineType, IEngineInstaller> delegatedInstallers;
+		readonly FrozenDictionary<EngineType, IEngineInstaller> delegatedInstallers;
 
 		/// <summary>
 		/// Initializes a new instance of the <see cref="DelegatingEngineInstaller"/> class.
 		/// </summary>
 		/// <param name="delegatedInstallers">The value of <see cref="delegatedInstallers"/>.</param>
-		public DelegatingEngineInstaller(IReadOnlyDictionary<EngineType, IEngineInstaller> delegatedInstallers)
+		public DelegatingEngineInstaller(FrozenDictionary<EngineType, IEngineInstaller> delegatedInstallers)
 		{
 			this.delegatedInstallers = delegatedInstallers ?? throw new ArgumentNullException(nameof(delegatedInstallers));
 		}
diff --git a/src/Tgstation.Server.Host/Core/Application.cs b/src/Tgstation.Server.Host/Core/Application.cs
index 202b098d7c..3b80d9da38 100644
--- a/src/Tgstation.Server.Host/Core/Application.cs
+++ b/src/Tgstation.Server.Host/Core/Application.cs
@@ -1,4 +1,5 @@
 using System;
+using System.Collections.Frozen;
 using System.Collections.Generic;
 using System.Globalization;
 using System.Threading.Tasks;
@@ -380,12 +381,13 @@ namespace Tgstation.Server.Host.Core
 							openDreamRepositoryDirectory),
 						new NoopEventConsumer()));
 
-			services.AddSingleton<IReadOnlyDictionary<EngineType, IEngineInstaller>>(
+			services.AddSingleton(
 				serviceProvider => new Dictionary<EngineType, IEngineInstaller>
 				{
 					{ EngineType.Byond, serviceProvider.GetRequiredService<ByondInstallerBase>() },
 					{ EngineType.OpenDream, serviceProvider.GetRequiredService<OpenDreamInstaller>() },
-				});
+				}
+				.ToFrozenDictionary());
 			services.AddSingleton<IEngineInstaller, DelegatingEngineInstaller>();
 
 			if (postSetupServices.InternalConfiguration.UsingSystemD)