diff --git a/install.sh b/install.sh
index 1dae949..d4b8679 100755
--- a/install.sh
+++ b/install.sh
@@ -79,6 +79,8 @@ if [ "${1:-}" = "-update" ]; then
         sudo_if mkdir -p "$BACKUP_DIR"
         BACKUP_FILE="$BACKUP_DIR/expenses-$(date +%Y%m%d-%H%M%S).db"
         sudo_if cp "$INSTALL_DIR/expenses.db" "$BACKUP_FILE"
+        # Restore ownership so the app user can still write to the database.
+        sudo_if chown --reference="$INSTALL_DIR/expenses.db" "$BACKUP_FILE" 2>/dev/null || true
         info "Database backed up to $BACKUP_FILE"
     fi