diff --git a/NEWS.md b/NEWS.md
index ab9e4d46e..76375c8e0 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -18,6 +18,8 @@
 
 * Improves documentation related to the hyperparameters associated with extracted objects that are generated from submodels. See the "Extracting with submodels" section of `?collect_extracts` to learn more.
 
+* `augment()` methods to `tune_results`, `resample_results`, and `last_fit` objects now always returns tibbles (#759).
+
 # tune 1.1.2
 
 * `last_fit()` now works with the 3-way validation split objects from `rsample::initial_validation_split()`. `last_fit()` and `fit_best()` now have a new argument `add_validation_set` to include or exclude the validation set in the dataset used to fit the model (#701).
diff --git a/R/augment.R b/R/augment.R
index 5a249f294..d1d57a137 100644
--- a/R/augment.R
+++ b/R/augment.R
@@ -112,6 +112,11 @@ merge_pred <- function(dat, pred, y) {
       )
     )
   }
+
+  if (!tibble::is_tibble(dat)) {
+    dat <- tibble::as_tibble(dat)
+  }
+
   dat$.row <- 1:nrow(dat)
   dat <- dplyr::left_join(dat, pred, by = ".row")
   dat$.row <- NULL
diff --git a/tests/testthat/test-augment.R b/tests/testthat/test-augment.R
index ff170397b..cebc08521 100644
--- a/tests/testthat/test-augment.R
+++ b/tests/testthat/test-augment.R
@@ -6,6 +6,7 @@ test_that("augment fit_resamples", {
   lr_spec <- parsnip::logistic_reg() %>% parsnip::set_engine("glm")
 
   set.seed(1)
+  two_class_dat <- as.data.frame(two_class_dat)
   bt1 <- rsample::bootstraps(two_class_dat, times = 30)
 
   set.seed(1)
@@ -23,6 +24,7 @@ test_that("augment fit_resamples", {
   expect_true(sum(names(aug_1) == ".pred_Class1") == 1)
   expect_true(sum(names(aug_1) == ".pred_Class2") == 1)
   expect_true(sum(names(aug_1) == ".resid") == 0)
+  expect_s3_class_bare_tibble(aug_1)
 
   expect_snapshot(error = TRUE, augment(fit_1, hey = "you"))
 })
@@ -33,6 +35,7 @@ test_that("augment fit_resamples", {
   lr_spec <- parsnip::logistic_reg() %>% parsnip::set_engine("glm")
 
   set.seed(1)
+  two_class_dat <- as.data.frame(two_class_dat)
   bt2 <- rsample::bootstraps(two_class_dat, times = 3)
 
   set.seed(1)
@@ -50,6 +53,7 @@ test_that("augment fit_resamples", {
   expect_true(sum(names(aug_2) == ".pred_class") == 1)
   expect_true(sum(names(aug_2) == ".pred_Class1") == 1)
   expect_true(sum(names(aug_2) == ".pred_Class2") == 1)
+  expect_s3_class_bare_tibble(aug_2)
 })
 
 # ------------------------------------------------------------------------------
@@ -77,6 +81,7 @@ test_that("augment tune_grid", {
   expect_true(sum(!is.na(aug_1$.pred)) == nrow(mtcars))
   expect_true(sum(names(aug_1) == ".pred") == 1)
   expect_true(sum(names(aug_1) == ".resid") == 1)
+  expect_s3_class_bare_tibble(aug_1)
 
   aug_2 <- augment(fit_1, parameters = data.frame(cost = 3))
   expect_true(any(abs(aug_1$.pred - aug_2$.pred) > 1))
@@ -113,6 +118,7 @@ test_that("augment tune_grid", {
   expect_true(sum(!is.na(aug_3$.pred)) == nrow(mtcars))
   expect_true(sum(names(aug_3) == ".pred") == 1)
   expect_true(sum(names(aug_3) == ".resid") == 1)
+  expect_s3_class_bare_tibble(aug_3)
 })
 
 
@@ -131,6 +137,7 @@ test_that("augment last_fit", {
   expect_true(sum(names(aug_1) == ".pred_class") == 1)
   expect_true(sum(names(aug_1) == ".pred_Class1") == 1)
   expect_true(sum(names(aug_1) == ".pred_Class2") == 1)
+  expect_s3_class_bare_tibble(aug_1)
 
   expect_snapshot(error = TRUE, augment(fit_1, potato = TRUE))
 })