diff --git a/novaclient/base.py b/novaclient/base.py
index a5dad823f..d270b316e 100644
--- a/novaclient/base.py
+++ b/novaclient/base.py
@@ -353,7 +353,8 @@ def _boot(self, resource_url, response_key, name, image, flavor,
         # either an open file *or* some contents as files here.
         if files:
             personality = body['server']['personality'] = []
-            for filepath, file_or_string in files.items():
+            for filepath, file_or_string in sorted(files.items(),
+                                                   key=lambda x: x[0]):
                 if hasattr(file_or_string, 'read'):
                     data = file_or_string.read()
                 else: