diff --git a/cmdline/CtaAdminCmd.hpp b/cmdline/CtaAdminCmd.hpp
index 5fbd554251a842db9b54616c832ee532f29686df..f86617efd084bc3377ae0ac6221044a7683a139b 100644
--- a/cmdline/CtaAdminCmd.hpp
+++ b/cmdline/CtaAdminCmd.hpp
@@ -40,7 +40,7 @@ public:
       return c;
    }
    static std::string jsonCloseDelim() {
-      return is_first_record ? "" : "]";
+      return is_first_record ? "[]" : "]";
    }
 
    // Static method to convert time to string