diff --git a/src/matrix/registration/types.ts b/src/matrix/registration/types.ts
index aa319d43..d79fd33a 100644
--- a/src/matrix/registration/types.ts
+++ b/src/matrix/registration/types.ts
@@ -24,7 +24,7 @@ export type AccountDetails = {
 export type RegistrationResponse = RegistrationResponseMoreDataNeeded | RegistrationResponseError | RegistrationResponseSuccess;
 
 export type RegistrationResponseMoreDataNeeded = {
-    completed: string[];
+    completed?: string[];
     flows: RegistrationFlow[];
     params: Record<string, any>;
     session: string;