diff --git a/salt/loader.py b/salt/loader.py
index 76bbbde80b..70dbfcb3e6 100644
--- a/salt/loader.py
+++ b/salt/loader.py
@@ -393,7 +393,7 @@ def grains(opts, force_refresh=False):
         if opts.get('grains_cache', False):
             cfn = os.path.join(
                 opts['cachedir'],
-                '{0}.cache.p'.format('grains')
+                'grains.cache.p'
             )
             if os.path.isfile(cfn):
                 grains_cache_age = int(time.time() - os.path.getmtime(cfn))