diff --git a/src/matrix/e2ee/megolm/keybackup/KeyBackup.ts b/src/matrix/e2ee/megolm/keybackup/KeyBackup.ts
index 49771d15..2de71491 100644
--- a/src/matrix/e2ee/megolm/keybackup/KeyBackup.ts
+++ b/src/matrix/e2ee/megolm/keybackup/KeyBackup.ts
@@ -88,7 +88,7 @@ export class KeyBackup {
                         throw err;
                     }
                 }
-                this.markKeysAsBackedUp(keysNeedingBackup, setAbortable);
+                await this.markKeysAsBackedUp(keysNeedingBackup, setAbortable);
                 amountFinished += keysNeedingBackup.length;
                 setProgress(new Progress(total, amountFinished));
             }