diff --git a/lib/tz_world.ex b/lib/tz_world.ex
index ca83220..bc80b2b 100644
--- a/lib/tz_world.ex
+++ b/lib/tz_world.ex
@@ -247,11 +247,4 @@ defmodule TzWorld do
       )
   end
 
-  # Returns the data directory for timezone data
-  @doc false
-  def data_dir do
-    Application.get_env(:tz_world, :data_dir, List.to_string(:code.priv_dir(:tz_world)))
-    |> String.to_charlist
-  end
-
 end
diff --git a/lib/tz_world/backend/dets.ex b/lib/tz_world/backend/dets.ex
index 4002103..fa80de9 100644
--- a/lib/tz_world/backend/dets.ex
+++ b/lib/tz_world/backend/dets.ex
@@ -47,9 +47,10 @@ defmodule TzWorld.Backend.Dets do
 
   @doc false
   def filename do
-    TzWorld.data_dir ++ '/timezones-geodata.dets'
+    TzWorld.GeoData.data_dir()
+    |> Path.join("timezones-geodata.dets")
+    |> String.to_charlist()
   end
-
   @doc false
   defp dets_options do
     [file: filename(), access: :read, estimated_no_objects: @slots]