diff --git a/script/execute.c b/script/execute.c
index ce9c669cf..2ec4f7f5a 100644
--- a/script/execute.c
+++ b/script/execute.c
@@ -197,7 +197,9 @@ grub_script_arglist_to_argv (struct grub_script_arglist *arglist,
 	      break;
 
 	    case GRUB_SCRIPT_ARG_TYPE_BLOCK:
-	      if (grub_script_argv_append (&result, arg->str) ||
+	      if (grub_script_argv_append (&result, "{") ||
+		  grub_script_argv_append (&result, arg->str) ||
+		  grub_script_argv_append (&result, "}") ||
 		  grub_script_argv_script_append (&result, arg->block))
 		goto fail;
 	      break;