diff --git a/lib/cors_plug.ex b/lib/cors_plug.ex
index e94e9c2..a393c5a 100644
--- a/lib/cors_plug.ex
+++ b/lib/cors_plug.ex
@@ -26,6 +26,17 @@ defmodule CORSPlug do
     ]
   end
 
+  @doc false
+  def call(conn, options) do
+    conn = merge_resp_headers(conn, headers(conn, options))
+
+    case {options[:send_preflight_response?], conn.method} do
+      {true, "OPTIONS"} -> conn |> send_resp(204, "") |> halt()
+      {_, _method} -> conn
+    end
+  end
+
+  @doc false
   def init(options) do
     options
     |> prepare_cfg(Application.get_all_env(:cors_plug))
@@ -41,15 +52,6 @@ defmodule CORSPlug do
     |> Keyword.merge(options)
   end
 
-  def call(conn, options) do
-    conn = merge_resp_headers(conn, headers(conn, options))
-
-    case {options[:send_preflight_response?], conn.method} do
-      {true, "OPTIONS"} -> conn |> send_resp(204, "") |> halt()
-      {_, _method} -> conn
-    end
-  end
-
   # headers specific to OPTIONS request
   defp headers(conn = %Plug.Conn{method: "OPTIONS"}, options) do
     headers(%{conn | method: nil}, options) ++