diff --git a/package.json b/package.json
index e5b43354..694a4f0e 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "resend",
-  "version": "6.20.0",
+  "version": "6.20.1",
   "description": "Node.js library for the Resend API",
   "main": "./dist/index.cjs",
   "module": "./dist/index.mjs",
diff --git a/src/webhooks/interfaces/webhook-event.interface.ts b/src/webhooks/interfaces/webhook-event.interface.ts
index c79ef24d..ac59d9b2 100644
--- a/src/webhooks/interfaces/webhook-event.interface.ts
+++ b/src/webhooks/interfaces/webhook-event.interface.ts
@@ -81,8 +81,8 @@ interface ContactEventData {
   created_at: string;
   updated_at: string;
   email: string;
-  first_name?: string;
-  last_name?: string;
+  first_name?: string | null;
+  last_name?: string | null;
   unsubscribed: boolean;
 }