diff --git a/src/Framework/Traits.cs b/src/Framework/Traits.cs
index 9be74ea1bc8..6ec7dd3afad 100644
--- a/src/Framework/Traits.cs
+++ b/src/Framework/Traits.cs
@@ -188,6 +188,11 @@ internal class EscapeHatches
         /// </summary>
         public readonly bool AlwaysDoImmutableFilesUpToDateCheck = Environment.GetEnvironmentVariable("MSBUILDDONOTCACHEMODIFICATIONTIME") == "1";
 
+        /// <summary>
+        /// When copying over an existing file, copy directly into the existing file rather than deleting and recreating.
+        /// </summary>
+        public readonly bool CopyWithoutDelete = Environment.GetEnvironmentVariable("MSBUILDCOPYWITHOUTDELETE") == "1";
+
         /// <summary>
         /// Emit events for project imports.
         /// </summary>
diff --git a/src/Tasks/Copy.cs b/src/Tasks/Copy.cs
index 0485ae97b36..606677f3305 100644
--- a/src/Tasks/Copy.cs
+++ b/src/Tasks/Copy.cs
@@ -285,7 +285,10 @@ private void LogAlwaysRetryDiagnosticFromResources(string messageResourceName, p
                 MakeFileWriteable(destinationFileState, true);
             }
 
-            if (ChangeWaves.AreFeaturesEnabled(ChangeWaves.Wave17_8) && destinationFileState.FileExists && !destinationFileState.IsReadOnly)
+            if (ChangeWaves.AreFeaturesEnabled(ChangeWaves.Wave17_8) &&
+                Traits.Instance.EscapeHatches.CopyWithoutDelete != true &&
+                destinationFileState.FileExists &&
+                !destinationFileState.IsReadOnly)
             {
                 FileUtilities.DeleteNoThrow(destinationFileState.Name);
             }