diff --git a/test/ffmpex_test.exs b/test/ffmpex_test.exs
index 52d2459..51eb88b 100644
--- a/test/ffmpex_test.exs
+++ b/test/ffmpex_test.exs
@@ -66,7 +66,8 @@ defmodule FFmpexTest do
       |> add_input_file(@fixture)
       |> add_output_file(@output_path)
 
-    assert {:error, {_, 1}} = execute(command)
+    assert {:error, {_, exit_status}} = execute(command)
+    assert exit_status == 1 || exit_status == 8
   end
 
   test "can prepare arguments" do
@@ -88,7 +89,7 @@ defmodule FFmpexTest do
   test "can get output from stdout" do
     command =
       FFmpex.new_command()
-      |> add_input_file(@fixture) 
+      |> add_input_file(@fixture)
       |> to_stdout()
         |> add_file_option(option_f("avi"))
 
diff --git a/test/ffprobe_test.exs b/test/ffprobe_test.exs
index c5a60e6..a8e2ced 100755
--- a/test/ffprobe_test.exs
+++ b/test/ffprobe_test.exs
@@ -11,7 +11,8 @@ defmodule FFprobeTest do
   @fixture_non_media_file __ENV__.file
 
   test "correct duration" do
-    assert 21.0 == FFprobe.duration(@fixture)
+    duration = FFprobe.duration(@fixture)
+    assert duration > 20.9 && duration <= 21.0
   end
 
   test "handles N/A duration" do