diff --git a/django/template/loaders/cached.py b/django/template/loaders/cached.py
index 4c25acd5993..fb987a5e3a2 100644
--- a/django/template/loaders/cached.py
+++ b/django/template/loaders/cached.py
@@ -6,6 +6,7 @@ to load templates from them in order, caching the result.
 import hashlib
 from django.template.base import TemplateDoesNotExist
 from django.template.loader import BaseLoader, get_template_from_string, find_template_loader, make_origin
+from django.utils.encoding import force_bytes
 
 class Loader(BaseLoader):
     is_usable = True
@@ -40,7 +41,7 @@ class Loader(BaseLoader):
         key = template_name
         if template_dirs:
             # If template directories were specified, use a hash to differentiate
-            key = '-'.join([template_name, hashlib.sha1('|'.join(template_dirs)).hexdigest()])
+            key = '-'.join([template_name, hashlib.sha1(force_bytes('|'.join(template_dirs))).hexdigest()])
 
         if key not in self.template_cache:
             template, origin = self.find_template(template_name, template_dirs)
diff --git a/django/utils/cache.py b/django/utils/cache.py
index 0fceaa96e68..ecf0f831b26 100644
--- a/django/utils/cache.py
+++ b/django/utils/cache.py
@@ -181,7 +181,7 @@ def _generate_cache_key(request, method, headerlist, key_prefix):
     for header in headerlist:
         value = request.META.get(header, None)
         if value is not None:
-            ctx.update(value)
+            ctx.update(force_bytes(value))
     path = hashlib.md5(force_bytes(iri_to_uri(request.get_full_path())))
     cache_key = 'views.decorators.cache.cache_page.%s.%s.%s.%s' % (
         key_prefix, method, path.hexdigest(), ctx.hexdigest())
diff --git a/django/utils/crypto.py b/django/utils/crypto.py
index 57bc60dc4f8..94f717bb171 100644
--- a/django/utils/crypto.py
+++ b/django/utils/crypto.py
@@ -72,10 +72,10 @@ def get_random_string(length=12,
         # is better than absolute predictability.
         random.seed(
             hashlib.sha256(
-                "%s%s%s" % (
+                ("%s%s%s" % (
                     random.getstate(),
                     time.time(),
-                    settings.SECRET_KEY)
+                    settings.SECRET_KEY)).encode('utf-8')
                 ).digest())
     return ''.join([random.choice(allowed_chars) for i in range(length)])