diff --git a/lib/asciinema/asciicasts.ex b/lib/asciinema/asciicasts.ex
index b66e53c..3894ede 100644
--- a/lib/asciinema/asciicasts.ex
+++ b/lib/asciinema/asciicasts.ex
@@ -106,7 +106,7 @@ defmodule Asciinema.Asciicasts do
     PosterGenerator.generate(asciicast)
   end
 
-  def stdout_stream(asciicast_file_path) do
+  def stdout_stream(asciicast_file_path) when is_binary(asciicast_file_path) do
     asciicast =
       asciicast_file_path
       |> File.read!
@@ -118,7 +118,7 @@ defmodule Asciinema.Asciicasts do
     |> Map.get("stdout")
     |> Enum.map(&List.to_tuple/1)
   end
-  def stdout_stream(stdout_timing_path, stdout_data_path) do
+  def stdout_stream({stdout_timing_path, stdout_data_path}) do
     Stream.resource(
       fn -> open_stream_files(stdout_timing_path, stdout_data_path) end,
       &generate_stream_elem/1,
diff --git a/test/asciinema/asciicasts_test.exs b/test/asciinema/asciicasts_test.exs
index 88ccf16..6eedbd6 100644
--- a/test/asciinema/asciicasts_test.exs
+++ b/test/asciinema/asciicasts_test.exs
@@ -119,22 +119,22 @@ defmodule Asciinema.AsciicastsTest do
 
   describe "stdout_stream/2" do
     test "with gzipped files" do
-      stream = Asciicasts.stdout_stream("spec/fixtures/0.9.9/stdout.time",
-                                        "spec/fixtures/0.9.9/stdout")
+      stream = Asciicasts.stdout_stream({"spec/fixtures/0.9.9/stdout.time",
+                                         "spec/fixtures/0.9.9/stdout"})
       assert :ok == Stream.run(stream)
       assert [{1.234567, "foobar"}, {0.123456, "baz"}] == Enum.take(stream, 2)
     end
 
     test "with bzipped files" do
-      stream = Asciicasts.stdout_stream("spec/fixtures/0.9.8/stdout.time",
-                                        "spec/fixtures/0.9.8/stdout")
+      stream = Asciicasts.stdout_stream({"spec/fixtures/0.9.8/stdout.time",
+                                         "spec/fixtures/0.9.8/stdout"})
       assert :ok == Stream.run(stream)
       assert [{1.234567, "foobar"}, {0.123456, "baz"}] == Enum.take(stream, 2)
     end
 
     test "with bzipped files (utf-8 sequence split between frames)" do
-      stream = Asciicasts.stdout_stream("spec/fixtures/0.9.8/stdout-split.time",
-                                        "spec/fixtures/0.9.8/stdout-split")
+      stream = Asciicasts.stdout_stream({"spec/fixtures/0.9.8/stdout-split.time",
+                                         "spec/fixtures/0.9.8/stdout-split"})
       assert :ok == Stream.run(stream)
       assert [{1.234567, "xxżó"}, {0.123456, "łć"}, {2.0, "xx"}] == Enum.take(stream, 3)
     end