diff --git a/lib/speck/validation_metadata/attribute.ex b/lib/speck/validation_metadata/attribute.ex
index 8de4783..34c9a48 100644
--- a/lib/speck/validation_metadata/attribute.ex
+++ b/lib/speck/validation_metadata/attribute.ex
@@ -43,7 +43,7 @@ defmodule Speck.ValidationMetadata.Attribute do
 
   defp merge(nil = _params, [attribute | path], value, strategy)
     when not is_integer(attribute) do
-      %{attribute => merge(%{}, path, value, strategy)}
+      %{attribute => merge(nil, path, value, strategy)}
   end
 
   defp merge(params, [path], value, strategy) when is_map(params) do
diff --git a/test/validation_metadata/attribute_test.exs b/test/validation_metadata/attribute_test.exs
index e652577..53513d1 100644
--- a/test/validation_metadata/attribute_test.exs
+++ b/test/validation_metadata/attribute_test.exs
@@ -12,6 +12,26 @@ defmodule Speck.ValidationMetadata.Attribute.Test do
       %{"state" => %{"reported" => %{"serial" => "sn1234"}}}
   end
 
+  test "merge nested lists" do
+    attributes = [
+      {["state", "reported", "a", 0, "b", 0, "c", 0, "d", 0, "id"], :unknown, 1001},
+      {["state", "reported", "a", 1, "b", 0, "c", 0, "d", 0, "id"], :unknown, 1002},
+    ]
+
+    params = %{state: %{reported: %{}}}
+
+    assert Attribute.merge(attributes, params) == %{
+      "state" => %{
+        "reported" => %{
+          "a" => [
+            %{"b" => [%{"c" => [%{"d" => [%{"id" => 1001}]}]}]},
+            %{"b" => [%{"c" => [%{"d" => [%{"id" => 1002}]}]}]},
+          ]
+        }
+      }
+    }
+  end
+
   describe "merge strategy" do
     test "attribute priority" do
       params = %{"name" => "Test Device"}