diff --git a/tests/test_cachefiles.py b/tests/test_cachefiles.py
index d3c2902..957b132 100644
--- a/tests/test_cachefiles.py
+++ b/tests/test_cachefiles.py
@@ -1,5 +1,10 @@
+from django.conf import settings
+from hashlib import md5
 from imagekit.cachefiles import ImageCacheFile
-from nose.tools import raises
+from imagekit.cachefiles.backends import Simple
+from nose.tools import raises, eq_
+import random
+import string
 from .imagegenerators import TestSpec
 from .utils import (assert_file_is_truthy, assert_file_is_falsy,
                     DummyAsyncCacheFileBackend, get_unique_image_file)
@@ -41,3 +46,32 @@ def test_no_source_error():
     spec = TestSpec(source=None)
     file = ImageCacheFile(spec)
     file.generate()
+
+
+def test_memcached_cache_key():
+    """
+    Ensure the default cachefile backend is sanitizing its cache key for
+    memcached by default.
+
+    """
+
+    class MockFile(object):
+        def __init__(self, name):
+            self.name = name
+
+    backend = Simple()
+    extra_char_count = len('state-') + len(settings.IMAGEKIT_CACHE_PREFIX)
+
+    length = 199 - extra_char_count
+    filename = '1' * length
+    file = MockFile(filename)
+    eq_(backend.get_key(file), '%s%s-state' %
+        (settings.IMAGEKIT_CACHE_PREFIX, file.name))
+
+    length = 200 - extra_char_count
+    filename = '1' * length
+    file = MockFile(filename)
+    eq_(backend.get_key(file), '%s%s:%s' % (
+        settings.IMAGEKIT_CACHE_PREFIX,
+        '1' * (200 - len(':') - 32 - len(settings.IMAGEKIT_CACHE_PREFIX)),
+        md5('%s%s-state' % (settings.IMAGEKIT_CACHE_PREFIX, filename)).hexdigest()))