diff --git a/Doorstop b/Doorstop
index 04d29898..b45c8415 160000
--- a/Doorstop
+++ b/Doorstop
@@ -1 +1 @@
-Subproject commit 04d2989813eaec3d98859333d0ad563ac292c714
+Subproject commit b45c8415cd3cfe59c6e79f90955bfc7a07204e13
diff --git a/IPA.Injector/Injector.cs b/IPA.Injector/Injector.cs
index c6ae0eb3..4c0d7fe0 100644
--- a/IPA.Injector/Injector.cs
+++ b/IPA.Injector/Injector.cs
@@ -109,13 +109,15 @@ namespace IPA.Injector
             }
 
             if (modified)
+            {
                 unityAsmDef.Write(unityPath);
+            }
             #endregion
 
             loader.Debug("Ensuring Assembly-CSharp is virtualized");
             #region Virtualize Assembly-CSharp.dll
             var ascPath = Path.Combine(Environment.CurrentDirectory, "Beat Saber_Data", "Managed", "Assembly-CSharp.dll");
-
+            
             var ascModule = VirtualizedModule.Load(ascPath);
             ascModule.Virtualize(cAsmName);
             #endregion
diff --git a/IPA.Injector/Virtualizer.cs b/IPA.Injector/Virtualizer.cs
index d80c65dc..21daec52 100644
--- a/IPA.Injector/Virtualizer.cs
+++ b/IPA.Injector/Virtualizer.cs
@@ -36,7 +36,7 @@ namespace IPA.Injector
         /// 
         /// </summary>
         /// <param name="module"></param>
-        public void Virtualize(AssemblyName selfName)
+        public void Virtualize(AssemblyName selfName, Action beforeChangeCallback = null)
         {
             bool changed = false;
             bool virtualize = true;
@@ -65,7 +65,10 @@ namespace IPA.Injector
             }
 
             if (changed)
+            {
+                beforeChangeCallback?.Invoke();
                 module.Write(file.FullName);
+            }
         }
 
         private void VirtualizeType(TypeDefinition type)
diff --git a/IPA/Program.cs b/IPA/Program.cs
index 415c0511..e6edc75b 100644
--- a/IPA/Program.cs
+++ b/IPA/Program.cs
@@ -254,6 +254,9 @@ namespace IPA
                     CopyAll(new DirectoryInfo(context.IPARoot), new DirectoryInfo(context.ProjectRoot), force,
                         backup,
                         null, false);
+
+                    backup.Add(context.AssemblyFile);
+                    backup.Add(context.EngineFile);
                 }
 
                 #region Create Plugin Folder