diff --git a/lib/outlook/internal_tree/raw_internal_basic.ex b/lib/outlook/internal_tree/raw_internal_basic.ex
index eda2060..cdaaf84 100644
--- a/lib/outlook/internal_tree/raw_internal_basic.ex
+++ b/lib/outlook/internal_tree/raw_internal_basic.ex
@@ -36,7 +36,7 @@ defmodule Outlook.InternalTree.RawInternalBasic do
     [ %InternalNode{node | content: case get_sibling_collocation(node.content) do
         :block -> partition_blocklevel(node.content)
         :inline -> inline_to_translation_units(node.content)
-        _ -> [ node ]
+        nil -> node.content
       end
     } | partition_blocklevel(rest) ]
   end