diff --git a/R-package/tests/testthat/test_custom_objective.R b/R-package/tests/testthat/test_custom_objective.R
index a941e39c8..9fcbeca4d 100644
--- a/R-package/tests/testthat/test_custom_objective.R
+++ b/R-package/tests/testthat/test_custom_objective.R
@@ -28,6 +28,8 @@ test_that("custom objective works", {
                 objective=logregobj, eval_metric=evalerror)
   
   bst <- xgb.train(param, dtrain, num_round, watchlist)
+  expect_equal(class(bst), "xgb.Booster")
+  expect_equal(length(bst$raw), 1064)
   attr(dtrain, 'label') <- getinfo(dtrain, 'label')
   
   logregobjattr <- function(preds, dtrain) {
@@ -40,4 +42,6 @@ test_that("custom objective works", {
   param <- list(max.depth=2, eta=1, nthread = 2, silent=1, 
                 objective=logregobjattr, eval_metric=evalerror)
   bst <- xgb.train(param, dtrain, num_round, watchlist)
+  expect_equal(class(bst), "xgb.Booster")
+  expect_equal(length(bst$raw), 1064)
 })
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