diff --git a/R/tidyr-verbs.R b/R/tidyr-verbs.R
index 1f7227b0..1c665e5d 100644
--- a/R/tidyr-verbs.R
+++ b/R/tidyr-verbs.R
@@ -167,13 +167,12 @@ unnest_check_tsibble <- function(data, key, index) {
   data
 }
 
+#' Unnest a data frame consisting of tsibbles to a tsibble
+#'
 #' @param data A data frame contains homogenous tsibbles in the list-columns.
 #' @param cols Names of columns to unnest.
 #' @inheritParams as_tsibble
 #' @keywords internal
-#' @examples
-#' nested_stock %>% 
-#'   unnest_tsibble(cols = data, key = stock)
 #' @export
 unnest_tsibble <- function(data, cols, key = NULL, validate = TRUE) {
   if (missing(cols)) {
@@ -195,13 +194,13 @@ unnest_tsibble <- function(data, cols, key = NULL, validate = TRUE) {
     new_lst <- unnested_names[map_lgl(unnested_data, is_list)]
     old_lst <- data_names[map_lgl(data, is_list)]
     lst_cols <- setdiff(old_lst, new_lst)
-    # checking if the nested columns has `tbl_ts` class (only for the first row)
-    first_nested <- data[lst_cols][1L, ]
-    eval_col <- purrr::imap(first_nested, dplyr::first)
-    tsbl_col <- map_lgl(eval_col, is_tsibble)
+    # checking if the nested columns has `tbl_ts` class
+    tsbl_col <- map_lgl(data[lst_cols], validate_list_of_tsibble)
     if (sum(tsbl_col) == 0) {
-      abort("Unnested columns contain no tsibble object.")
+      abort("Unnested columns contain no tsibble columns.")
     }
+    first_nested <- data[lst_cols][1L, ]
+    eval_col <- purrr::imap(first_nested, dplyr::first)
 
     tsbl <- eval_col[tsbl_col][[1L]]
     idx <- index(tsbl)
diff --git a/man/unnest_tsibble.Rd b/man/unnest_tsibble.Rd
new file mode 100644
index 00000000..67a07e35
--- /dev/null
+++ b/man/unnest_tsibble.Rd
@@ -0,0 +1,24 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/tidyr-verbs.R
+\name{unnest_tsibble}
+\alias{unnest_tsibble}
+\title{Unnest a data frame consisting of tsibbles to a tsibble}
+\usage{
+unnest_tsibble(data, cols, key = NULL, validate = TRUE)
+}
+\arguments{
+\item{data}{A data frame contains homogenous tsibbles in the list-columns.}
+
+\item{cols}{Names of columns to unnest.}
+
+\item{key}{Unquoted variable(s) that uniquely determine time indices. \code{NULL} for
+empty key, and works with tidy selector (e.g. \code{\link[dplyr:starts_with]{dplyr::starts_with()}}).}
+
+\item{validate}{\code{TRUE} suggests to verify that each key or each combination
+of key variables leads to unique time indices (i.e. a valid tsibble). If you
+are sure that it's a valid input, specify \code{FALSE} to skip the checks.}
+}
+\description{
+Unnest a data frame consisting of tsibbles to a tsibble
+}
+\keyword{internal}
diff --git a/tests/testthat/test-tidyr.R b/tests/testthat/test-tidyr.R
index 475abe4c..ec223ad1 100644
--- a/tests/testthat/test-tidyr.R
+++ b/tests/testthat/test-tidyr.R
@@ -196,7 +196,7 @@ test_that("dplyr verbs for lst_ts", {
   # )
   expect_error(
     unnest_tsibble(nest_t %>% mutate(data = 1), cols = data),
-    "contain no tsibble object."
+    "contain no tsibble columns."
   )
   expect_is(nest_t %>% select(data2 = data), "lst_ts")
   expect_is(nest_t %>% group_by(State), "grouped_df")