Index: django/db/backends/sqlite3/base.py
===================================================================
--- django/db/backends/sqlite3/base.py	(revision 8472)
+++ django/db/backends/sqlite3/base.py	(working copy)
@@ -182,7 +182,7 @@
         dt = util.typecast_timestamp(dt)
     except (ValueError, TypeError):
         return None
-    return getattr(dt, lookup_type)
+    return unicode(getattr(dt, lookup_type))
 
 def _sqlite_date_trunc(lookup_type, dt):
     try: