diff --git a/gtk/gtktreeview.c b/gtk/gtktreeview.c
index e8191a9fef..1a4ed0488a 100644
--- a/gtk/gtktreeview.c
+++ b/gtk/gtktreeview.c
@@ -5614,6 +5614,8 @@ validate_row (GtkTreeView   *tree_view,
       if (is_separator)
         {
           height = separator_height;
+          /* gtk_tree_view_get_row_height() assumes separator nodes are > 0 */
+          height = MAX (height, 1);
         }
       else
         {