diff --git a/lib/nerves_hub_link.ex b/lib/nerves_hub_link.ex
index af1c5c6..00dabf1 100644
--- a/lib/nerves_hub_link.ex
+++ b/lib/nerves_hub_link.ex
@@ -53,6 +53,6 @@ defmodule NervesHubLink do
   @doc """
   Send a file to the connected console
   """
-  @spec send_file(Path.t()) :: :ok
+  @spec send_file(Path.t()) :: :ok | {:error, :too_large | File.posix()}
   defdelegate send_file(file_path), to: Socket
 end
diff --git a/lib/nerves_hub_link/socket.ex b/lib/nerves_hub_link/socket.ex
index bd0d3ee..288ac56 100644
--- a/lib/nerves_hub_link/socket.ex
+++ b/lib/nerves_hub_link/socket.ex
@@ -49,6 +49,7 @@ defmodule NervesHubLink.Socket do
     GenServer.call(__MODULE__, {:check_connection, type})
   end
 
+  @spec send_file(Path.t()) :: :ok | {:error, :too_large | File.posix()}
   def send_file(file_path) do
     GenServer.call(__MODULE__, {:send_file, file_path})
   end
diff --git a/lib/nerves_hub_link/upload_file.ex b/lib/nerves_hub_link/upload_file.ex
index e21fc37..4d33788 100644
--- a/lib/nerves_hub_link/upload_file.ex
+++ b/lib/nerves_hub_link/upload_file.ex
@@ -18,6 +18,7 @@ defmodule NervesHubLink.UploadFile do
     defstruct [:file_path, :socket_pid]
   end
 
+  @spec start_link(Path.t(), pid()) :: GenServer.on_start()
   def start_link(file_path, socket_pid) do
     GenServer.start_link(__MODULE__, file_path: file_path, socket_pid: socket_pid)
   end
@@ -38,7 +39,7 @@ defmodule NervesHubLink.UploadFile do
 
     :ok = Socket.start_uploading(state.socket_pid, filename)
 
-    File.stream!(state.file_path, [], 1024)
+    File.stream!(state.file_path, 1024)
     |> Stream.with_index()
     |> Stream.each(fn {chunk, index} ->
       :ok = Socket.upload_data(state.socket_pid, filename, index, chunk)