diff --git a/packages/taler-wallet-core/src/types/backupTypes.ts b/packages/taler-wallet-core/src/types/backupTypes.ts
index 6e65cd72a..6bdf26992 100644
--- a/packages/taler-wallet-core/src/types/backupTypes.ts
+++ b/packages/taler-wallet-core/src/types/backupTypes.ts
@@ -81,6 +81,14 @@ export interface WalletBackupContentV1 {
    */
   wallet_root_pub: string;
 
+  /**
+   * Current device identifier that "owns" the backup.
+   * 
+   * This identifier allows one wallet to notice when another
+   * wallet is "alive" and connected to the same sync provider.
+   */
+  current_device_id: string;
+
   /**
    * Per-exchange data sorted by exchange master public key.
    *