diff --git a/django/core/cache/backends/base.py b/django/core/cache/backends/base.py
index d527e44d8b3..06e8952bfb5 100644
--- a/django/core/cache/backends/base.py
+++ b/django/core/cache/backends/base.py
@@ -1,9 +1,9 @@
 "Base Cache class."
+from __future__ import unicode_literals
 
 import warnings
 
 from django.core.exceptions import ImproperlyConfigured, DjangoRuntimeWarning
-from django.utils.encoding import smart_bytes
 from django.utils.importlib import import_module
 
 class InvalidCacheBackendError(ImproperlyConfigured):
@@ -23,7 +23,7 @@ def default_key_func(key, key_prefix, version):
     the `key_prefix'. KEY_FUNCTION can be used to specify an alternate
     function with custom key making behavior.
     """
-    return ':'.join([key_prefix, str(version), smart_bytes(key)])
+    return ':'.join([key_prefix, str(version), key])
 
 def get_key_func(key_func):
     """
@@ -62,7 +62,7 @@ class BaseCache(object):
         except (ValueError, TypeError):
             self._cull_frequency = 3
 
-        self.key_prefix = smart_bytes(params.get('KEY_PREFIX', ''))
+        self.key_prefix = params.get('KEY_PREFIX', '')
         self.version = params.get('VERSION', 1)
         self.key_func = get_key_func(params.get('KEY_FUNCTION', None))
 
diff --git a/django/utils/cache.py b/django/utils/cache.py
index 95b0fba07b2..edac6ec75df 100644
--- a/django/utils/cache.py
+++ b/django/utils/cache.py
@@ -16,6 +16,7 @@ cache keys to prevent delivery of wrong content.
 An example: i18n middleware would need to distinguish caches by the
 "Accept-language" header.
 """
+from __future__ import unicode_literals
 
 import hashlib
 import re
@@ -170,7 +171,7 @@ def _i18n_cache_key_suffix(request, cache_key):
         # User-defined tzinfo classes may return absolutely anything.
         # Hence this paranoid conversion to create a valid cache key.
         tz_name = force_text(get_current_timezone_name(), errors='ignore')
-        cache_key += '.%s' % tz_name.encode('ascii', 'ignore').replace(' ', '_')
+        cache_key += '.%s' % tz_name.encode('ascii', 'ignore').decode('ascii').replace(' ', '_')
     return cache_key
 
 def _generate_cache_key(request, method, headerlist, key_prefix):
diff --git a/tests/regressiontests/cache/tests.py b/tests/regressiontests/cache/tests.py
index 8fc749aaa27..4ffca2d4583 100644
--- a/tests/regressiontests/cache/tests.py
+++ b/tests/regressiontests/cache/tests.py
@@ -1308,7 +1308,7 @@ class CacheI18nTest(TestCase):
         # This is tightly coupled to the implementation,
         # but it's the most straightforward way to test the key.
         tz = force_text(timezone.get_current_timezone_name(), errors='ignore')
-        tz = tz.encode('ascii', 'ignore').replace(' ', '_')
+        tz = tz.encode('ascii', 'ignore').decode('ascii').replace(' ', '_')
         response = HttpResponse()
         key = learn_cache_key(request, response)
         self.assertIn(tz, key, "Cache keys should include the time zone name when time zones are active")
@@ -1320,7 +1320,7 @@ class CacheI18nTest(TestCase):
         request = self._get_request()
         lang = translation.get_language()
         tz = force_text(timezone.get_current_timezone_name(), errors='ignore')
-        tz = tz.encode('ascii', 'ignore').replace(' ', '_')
+        tz = tz.encode('ascii', 'ignore').decode('ascii').replace(' ', '_')
         response = HttpResponse()
         key = learn_cache_key(request, response)
         self.assertNotIn(lang, key, "Cache keys shouldn't include the language name when i18n isn't active")