diff --git a/R/htanno-.R b/R/htanno-.R
index 55d1b26e..ccbce764 100644
--- a/R/htanno-.R
+++ b/R/htanno-.R
@@ -188,7 +188,10 @@ HtannoProto <- ggplot2::ggproto("HtannoProto",
     # otherwise, they won't be collected.
     extra_params = character(),
     setup_params = function(self) .subset2(self, "params"),
-    setup_data = function(self) .subset2(self, "data"),
+
+    # use `NULL`, if you don't need any data from the heatmap
+    # use `.subset2(self, "data")` if you want to attach the matrix
+    setup_data = function(self) NULL,
 
     # Following fields should be defined for the new `Htanno` object.
     # argument name in the function doesn't matter.
diff --git a/R/htanno-gg.R b/R/htanno-gg.R
index 8e0c8535..02414b5b 100644
--- a/R/htanno-gg.R
+++ b/R/htanno-gg.R
@@ -44,6 +44,18 @@ gganno_left <- function(...) htanno_gg(position = "left", ...)
 gganno_right <- function(...) htanno_gg(position = "right", ...)
 
 HtannoGG <- ggplot2::ggproto("HtannoGG", HtannoProto,
+    setup_data = function(self) {
+        data <- .subset2(self, "data")
+        # matrix: will be reshaped to the long-format data.frame
+        # data.frame: won't do any thing special
+        if (is.matrix(data)) {
+            data <- melt_matrix(data)
+        } else {
+            data <- as_tibble0(data, rownames = ".row_names")
+            data$.row_index <- seq_len(nrow(data))
+        }
+        data
+    },
     ggplot = function(self, mapping) {
         ans <- ggplot2::ggplot(mapping = mapping) +
             ggplot2::theme_bw()
@@ -57,14 +69,6 @@ HtannoGG <- ggplot2::ggproto("HtannoGG", HtannoProto,
     draw = function(self, panels, index) {
         data <- .subset2(self, "data")
         axis <- to_coord_axis(.subset2(self, "position"))
-        # matrix: will be reshaped to the long-format data.frame
-        # data.frame: won't do any thing special
-        if (is.matrix(data)) {
-            data <- melt_matrix(data)
-        } else {
-            data <- as_tibble0(data, rownames = ".row_names")
-            data$.row_index <- seq_len(nrow(data))
-        }
         coords <- data_frame0(.panel = panels[index], .index = index)
         coords[[paste0(".", axis)]] <- seq_along(index)
         data <- merge(data, coords,
diff --git a/R/htanno-reorder.R b/R/htanno-reorder.R
index b9b784be..ee664a4a 100644
--- a/R/htanno-reorder.R
+++ b/R/htanno-reorder.R
@@ -38,6 +38,7 @@ htanno_reorder <- function(fun = rowMeans, ..., strict = TRUE,
 }
 
 HtannoReorder <- ggplot2::ggproto("HtannoReorder", HtannoProto,
+    setup_data = function(self) .subset2(self, "data"),
     compute = function(self, panels, index, fun, fun_params, strict) {
         data <- .subset2(self, "data")
         position <- .subset2(self, "position")
diff --git a/R/initialize-htanno.R b/R/initialize-htanno.R
index 30192207..0f31d34e 100644
--- a/R/initialize-htanno.R
+++ b/R/initialize-htanno.R
@@ -66,9 +66,12 @@ initialize_htanno_layout <- function(object, heatmap, object_name) {
     params <- object$setup_params()
     object$params <- params
 
-    # prepare data --------------------------------------
-    data <- object$setup_data()
-    object$data <- data
+    # rows are observations, this data came from `htanno_setup_data`, which can
+    # be used to check the axis dimention
+    data <- .subset2(object, "data")
+
+    # set up data --------------------------------------
+    object$data <- object$setup_data()
 
     # prepare old layout --------------------------------
     old_panels <- slot(heatmap, paste0(axis, "_panels"))
diff --git a/tests/testthat/_snaps/htanno/dendro.png b/tests/testthat/_snaps/htanno/dendro.png
index 91e52c60..d9b27ce1 100644
Binary files a/tests/testthat/_snaps/htanno/dendro.png and b/tests/testthat/_snaps/htanno/dendro.png differ
diff --git a/tests/testthat/_snaps/htanno/dendro_cutree.png b/tests/testthat/_snaps/htanno/dendro_cutree.png
index 4e63f5d4..581a2ef1 100644
Binary files a/tests/testthat/_snaps/htanno/dendro_cutree.png and b/tests/testthat/_snaps/htanno/dendro_cutree.png differ
diff --git a/tests/testthat/_snaps/htanno/dendro_left_between_group_reorder.png b/tests/testthat/_snaps/htanno/dendro_left_between_group_reorder.png
index 7304a5b3..dcd78e65 100644
Binary files a/tests/testthat/_snaps/htanno/dendro_left_between_group_reorder.png and b/tests/testthat/_snaps/htanno/dendro_left_between_group_reorder.png differ
diff --git a/tests/testthat/_snaps/htanno/dendro_top_between_group.png b/tests/testthat/_snaps/htanno/dendro_top_between_group.png
index b4745746..883463aa 100644
Binary files a/tests/testthat/_snaps/htanno/dendro_top_between_group.png and b/tests/testthat/_snaps/htanno/dendro_top_between_group.png differ