diff --git a/libs/common/src/tools/generator/username/email-forwarders/fastmail-forwarder.ts b/libs/common/src/tools/generator/username/email-forwarders/fastmail-forwarder.ts
index e8ea19afc9..85a7cf1c90 100644
--- a/libs/common/src/tools/generator/username/email-forwarders/fastmail-forwarder.ts
+++ b/libs/common/src/tools/generator/username/email-forwarders/fastmail-forwarder.ts
@@ -14,6 +14,8 @@ export class FastmailForwarder implements Forwarder {
       throw "Unable to obtain Fastmail masked email account ID.";
     }
 
+    const forDomain = (options.website || "");
+
     const requestInit: RequestInit = {
       redirect: "manual",
       cache: "no-store",
@@ -35,7 +37,7 @@ export class FastmailForwarder implements Forwarder {
               "new-masked-email": {
                 state: "enabled",
                 description: "",
-                forDomain: options.website,
+                forDomain: forDomain,
                 emailPrefix: options.fastmail.prefix,
               },
             },
diff --git a/libs/common/src/tools/generator/username/forwarders/fastmail.ts b/libs/common/src/tools/generator/username/forwarders/fastmail.ts
index e6ab28b59e..0236e658fb 100644
--- a/libs/common/src/tools/generator/username/forwarders/fastmail.ts
+++ b/libs/common/src/tools/generator/username/forwarders/fastmail.ts
@@ -12,7 +12,7 @@ import { Forwarders } from "../options/constants";
 import { EmailPrefixOptions, ApiOptions } from "../options/forwarder-options";
 
 export const DefaultFastmailOptions: ApiOptions & EmailPrefixOptions = Object.freeze({
-  website: null,
+  website: "",
   domain: "",
   prefix: "",
   token: "",