diff --git a/src/xhrInterceptor/responseModifiers/createMessageRemoveParentRef.ts b/src/xhrInterceptor/responseModifiers/createMessageRemoveParentRef.ts
new file mode 100644
index 0000000..5fa59b5
--- /dev/null
+++ b/src/xhrInterceptor/responseModifiers/createMessageRemoveParentRef.ts
@@ -0,0 +1,18 @@
+import { Modifier } from "./types";
+
+const createMessageRemoveParentRef: Modifier = {
+  urlRegex: /api\/CreateMessage/i,
+  featureGated: true,
+  features: ['flattenthreads', 'flattenthreads_switch_enabled'],
+  isEnabled(options) {
+    return options['flattenthreads'] &&
+        options['flattenthreads_switch_enabled'];
+  },
+  async interceptor(response) {
+    // Remove parent_message_id value (field 37)
+    delete response[37];
+    return response;
+  }
+};
+
+export default createMessageRemoveParentRef;