diff --git a/django/contrib/sessions/backends/db.py b/django/contrib/sessions/backends/db.py
index 0d68f13e68..85c4a0dd3c 100644
--- a/django/contrib/sessions/backends/db.py
+++ b/django/contrib/sessions/backends/db.py
@@ -3,6 +3,7 @@ from django.contrib.sessions.models import Session
 from django.contrib.sessions.backends.base import SessionBase, CreateError
 from django.core.exceptions import SuspiciousOperation
 from django.db import IntegrityError, transaction
+from django.utils.encoding import force_unicode
 
 class SessionStore(SessionBase):
     """
@@ -14,7 +15,7 @@ class SessionStore(SessionBase):
                 session_key = self.session_key,
                 expire_date__gt=datetime.datetime.now()
             )
-            return self.decode(s.session_data)
+            return self.decode(force_unicode(s.session_data))
         except (Session.DoesNotExist, SuspiciousOperation):
             self.create()
             return {}