diff --git a/R/dim_names.R b/R/dim_names.R
index b11ceef..12cabbe 100644
--- a/R/dim_names.R
+++ b/R/dim_names.R
@@ -69,14 +69,14 @@ union_dim_names <- function(x) {
 }
 
 intersect_dim_names <- function(x) {
-  purrr::modify(purrr::list_transpose(x),
+  purrr::modify(purrr::list_transpose(x, simplify = FALSE),
                 function(x) {
                   purrr::reduce(x, set_intersect)
                 })
 }
 
 diff_dim_names <- function(x) {
-  purrr::modify(purrr::list_transpose(x),
+  purrr::modify(purrr::list_transpose(x, simplify = FALSE),
                 function(x) {
                   purrr::reduce(x, set_diff)
                 })
diff --git a/tests/testthat/test-rbind.R b/tests/testthat/test-rbind.R
index f851e21..edea894 100644
--- a/tests/testthat/test-rbind.R
+++ b/tests/testthat/test-rbind.R
@@ -33,4 +33,30 @@ test_that("rbind.ddf_col() and rbind.tbl_ddf() work", {
                  filter(axis1 %in% dimnames(ddf_col2)[["axis1"]],
                         axis2 %in% dimnames(ddf_col2)[["axis2"]]),
                ddf_col2)
+
+  # works when the number of key rows is 1 (#23)
+  data_1 <- tidyr::expand_grid(key = tibble::tibble(col_1 = 1,
+                                                    col_2 = 1)) |>
+    tibble::add_column(value = 1) |>
+    dibble_by("key")
+
+  data_2 <- tidyr::expand_grid(key = tibble::tibble(col_1 = 2:3,
+                                                    col_2 = 2:3)) |>
+    tibble::add_column(value = 2) |>
+    dibble_by("key")
+
+  data_3 <- tidyr::expand_grid(key = tibble::tibble(col_1 = 2,
+                                                    col_2 = 2)) |>
+    tibble::add_column(value = 2) |>
+    dibble_by("key")
+
+  data_4 <- tidyr::expand_grid(key = tibble::tibble(col_1 = 2,
+                                                    col_2 = 2),
+                               key_2 = tibble::tibble(col_1 = 2)) |>
+    tibble::add_column(value = 2) |>
+    dibble_by("key", "key_2")
+
+  expect_no_error(broadcast(rbind(data_1, data_2), "key"))
+  expect_no_error(broadcast(rbind(data_1, data_3), "key"))
+  expect_no_error(broadcast(rbind(data_1, data_4), c("key", "key_2")))
 })