diff --git a/lib/types/backup-types.js b/lib/types/backup-types.js
--- a/lib/types/backup-types.js
+++ b/lib/types/backup-types.js
@@ -5,6 +5,8 @@
 
 import { tShape } from '../utils/validation-utils.js';
 
+// This type should match `BackupKeysResult` in
+// `native/native_rust_library/src/backup.rs`
 export type BackupKeys = {
   +backupID: string,
   +backupDataKey: string,
diff --git a/native/native_rust_library/src/backup.rs b/native/native_rust_library/src/backup.rs
--- a/native/native_rust_library/src/backup.rs
+++ b/native/native_rust_library/src/backup.rs
@@ -392,8 +392,11 @@
   })
 }
 
+// This struct should match `BackupKeys` in `lib/types/backup-types.js`
 #[derive(Debug, Serialize)]
+#[serde(rename_all = "camelCase")]
 struct BackupKeysResult {
+  #[serde(rename = "backupID")]
   backup_id: String,
   backup_data_key: String,
   backup_log_data_key: String,