diff --git a/OpenRA.Game/ModData.cs b/OpenRA.Game/ModData.cs
index d24dba8fda..98a19f3f88 100644
--- a/OpenRA.Game/ModData.cs
+++ b/OpenRA.Game/ModData.cs
@@ -217,6 +217,9 @@ namespace OpenRA
 			MapCache.Dispose();
 			if (VoxelLoader != null)
 				VoxelLoader.Dispose();
+
+			if (ObjectCreator != null)
+				ObjectCreator.Dispose();
 		}
 	}
 
diff --git a/OpenRA.Game/ObjectCreator.cs b/OpenRA.Game/ObjectCreator.cs
index c9c3c0aa03..afb8f32f17 100644
--- a/OpenRA.Game/ObjectCreator.cs
+++ b/OpenRA.Game/ObjectCreator.cs
@@ -18,7 +18,7 @@ using OpenRA.Primitives;
 
 namespace OpenRA
 {
-	public class ObjectCreator
+	public sealed class ObjectCreator : IDisposable
 	{
 		// .NET does not support unloading assemblies, so mod libraries will leak across mod changes.
 		// This tracks the assemblies that have been loaded since game start so that we don't load multiple copies
@@ -29,13 +29,6 @@ namespace OpenRA
 		readonly Pair<Assembly, string>[] assemblies;
 		readonly bool isMonoRuntime = Type.GetType("Mono.Runtime") != null;
 
-		public ObjectCreator(Assembly a)
-		{
-			typeCache = new Cache<string, Type>(FindType);
-			ctorCache = new Cache<Type, ConstructorInfo>(GetCtor);
-			assemblies = a.GetNamespaces().Select(ns => Pair.New(a, ns)).ToArray();
-		}
-
 		public ObjectCreator(Manifest manifest, FileSystem.FileSystem modFiles)
 		{
 			typeCache = new Cache<string, Type>(FindType);
@@ -76,7 +69,6 @@ namespace OpenRA
 
 			AppDomain.CurrentDomain.AssemblyResolve += ResolveAssembly;
 			assemblies = assemblyList.SelectMany(asm => asm.GetNamespaces().Select(ns => Pair.New(asm, ns))).ToArray();
-			AppDomain.CurrentDomain.AssemblyResolve -= ResolveAssembly;
 		}
 
 		Assembly ResolveAssembly(object sender, ResolveEventArgs e)
@@ -85,6 +77,9 @@ namespace OpenRA
 				if (a.FullName == e.Name)
 					return a;
 
+			if (assemblies == null)
+				return null;
+
 			return assemblies.Select(a => a.First).FirstOrDefault(a => a.FullName == e.Name);
 		}
 
@@ -159,6 +154,23 @@ namespace OpenRA
 				.SelectMany(ma => ma.GetTypes());
 		}
 
+		~ObjectCreator()
+		{
+			Dispose(false);
+		}
+
+		public void Dispose()
+		{
+			Dispose(true);
+			GC.SuppressFinalize(this);
+		}
+
+		void Dispose(bool disposing)
+		{
+			if (disposing)
+				AppDomain.CurrentDomain.AssemblyResolve -= ResolveAssembly;
+		}
+
 		[AttributeUsage(AttributeTargets.Constructor)]
 		public sealed class UseCtorAttribute : Attribute { }
 	}