diff --git a/src/api/models/user.ts b/src/api/models/user.ts
index 63f79908e3..46d32963bc 100644
--- a/src/api/models/user.ts
+++ b/src/api/models/user.ts
@@ -59,6 +59,7 @@ export type IUser = {
 	is_suspended: boolean;
 	keywords: string[];
 	host: string;
+	host_lower: string;
 	account: {
 		keypair: string;
 		email: string;
diff --git a/src/api/private/signup.ts b/src/api/private/signup.ts
index a4c06b5f5e..280153d4f5 100644
--- a/src/api/private/signup.ts
+++ b/src/api/private/signup.ts
@@ -120,6 +120,7 @@ export default async (req: express.Request, res: express.Response) => {
 		username: username,
 		username_lower: username.toLowerCase(),
 		host: null,
+		host_lower: null,
 		account: {
 			keypair: generateKeypair(),
 			token: secret,
diff --git a/tools/migration/shell.1522116710.user-host_lower.js b/tools/migration/shell.1522116710.user-host_lower.js
new file mode 100644
index 0000000000..31ec6c468a
--- /dev/null
+++ b/tools/migration/shell.1522116710.user-host_lower.js
@@ -0,0 +1 @@
+db.users.update({ }, { $set: { host_lower: null } }, { multi: true });