diff --git a/NEWS.md b/NEWS.md
index 89adae4..3088436 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -1,5 +1,9 @@
 # News 
 
+## metacoder 0.3.9.9000 (development version)
+
+* Fixed `heat_tree()` erroring with `The value <x> is not representable as an integer. Invalid value` when using `layout = "davidson-harel"` on a graph with a connected component larger than 1024 nodes. The `fineiter` argument passed to `igraph::layout_with_dh()` must be an integer, but was computed as `max(10, log2(vcount(graph)))`, which is non-integer once `vcount > 1024`. It is now rounded (issue [#362](https://github.com/grunwaldlab/metacoder/issues/362)).
+
 ## metacoder 0.3.9
 
 * Maintenance release to fix CRAN check issues.
diff --git a/R/heat_tree--layouts.R b/R/heat_tree--layouts.R
index cbc61e5..f68cc57 100644
--- a/R/heat_tree--layouts.R
+++ b/R/heat_tree--layouts.R
@@ -46,8 +46,13 @@ layout_functions <- function(name = NULL, graph = NULL, intitial_coords = NULL,
                      "reingold-tilford" = list(circular = TRUE,
                                                mode = "out"),
                      "davidson-harel" = list(coords = intitial_coords,
-                                             maxiter = 10 * effort,
-                                             fineiter = max(10, log2(igraph::vcount(graph))) * effort,
+                                             maxiter = round(10 * effort),
+                                             # `fineiter` is passed to igraph::layout_with_dh(), which
+                                             # requires an integer. `log2(vcount)` is non-integer once a
+                                             # (connected component of the) graph exceeds 1024 nodes, so
+                                             # round to avoid igraph's "not representable as an integer"
+                                             # error (grunwaldlab/metacoder#362).
+                                             fineiter = round(max(10, log2(igraph::vcount(graph))) * effort),
                                              cool.fact = 0.75 - effort * 0.1,
                                              weight.node.dist = 13, #* ifelse(is.null(v_weight), 1, list(rescale(v_weight, c(.1, 10))))[[1]], #higher values spread out nodes 
                                              weight.border = 0,