diff --git a/sql_caching/middleware.py b/sql_caching/middleware.py
index 24da6b0..2ef9372 100644
--- a/sql_caching/middleware.py
+++ b/sql_caching/middleware.py
@@ -8,11 +8,11 @@
 '''
 from threading import local
 import itertools
+from django.utils.deprecation import MiddlewareMixin
 from django.db.models.sql.compiler import SQLCompiler
 from django.db.models.sql.datastructures import EmptyResultSet
 from django.db.models.sql.constants import GET_ITERATOR_CHUNK_SIZE
 
-
 _thread_locals = local()
 
 
@@ -30,7 +30,7 @@ def execute_sql_cache(self, *args, **kwargs):
     if hasattr(_thread_locals, 'query_cache'):
 
         sql = get_sql(self)  # ('SELECT * FROM ...', (50)) <= sql string, args tuple
-        if sql[0][:6].upper() == 'SELECT':
+        if sql[0].upper().lstrip().startswith('SELECT'):
 
             # uses the tuple of sql + args as the cache key
             if sql in _thread_locals.query_cache:
@@ -57,7 +57,7 @@ def execute_sql_cache(self, *args, **kwargs):
     return self._execute_sql(*args, **kwargs)
 
 
-class QueryCacheMiddleware(object):
+class QueryCacheMiddleware(MiddlewareMixin):
     def process_request(self, request):
         _thread_locals.query_cache = {}