diff --git a/.gitignore b/.gitignore
index 480df8e..560b9b2 100644
--- a/.gitignore
+++ b/.gitignore
@@ -21,3 +21,4 @@ venv/
 demo.*
 .coverage
 coverage.xml
+tests/demo.*
diff --git a/tests/test_audio.py b/tests/test_audio.py
index c0d82f5..ef08f98 100644
--- a/tests/test_audio.py
+++ b/tests/test_audio.py
@@ -1,7 +1,10 @@
 # coding: utf-8
 
+import os
 from captcha.audio import AudioCaptcha
 
+ROOT = os.path.abspath(os.path.dirname(__file__))
+
 
 def test_audio_generate():
     captcha = AudioCaptcha()
@@ -14,3 +17,10 @@ def test_audio_random():
     captcha = AudioCaptcha()
     data = captcha.random(4)
     assert len(data) == 4
+
+
+def test_save_audio():
+    captcha = AudioCaptcha()
+    filepath = os.path.join(ROOT, 'demo.wav')
+    captcha.write('1234', filepath)
+    assert os.path.isfile(filepath)
diff --git a/tests/test_image.py b/tests/test_image.py
index 13f7143..963453c 100644
--- a/tests/test_image.py
+++ b/tests/test_image.py
@@ -1,9 +1,19 @@
 # coding: utf-8
 
+import os
 from captcha.image import ImageCaptcha
 
+ROOT = os.path.abspath(os.path.dirname(__file__))
+
 
 def test_image_generate():
     captcha = ImageCaptcha()
     data = captcha.generate('1234')
     assert hasattr(data, 'read')
+
+
+def test_save_image():
+    captcha = ImageCaptcha()
+    filepath = os.path.join(ROOT, 'demo.png')
+    captcha.write('1234', filepath)
+    assert os.path.isfile(filepath)