diff --git a/tldp/sources.py b/tldp/sources.py
index 1890817..a951caa 100644
--- a/tldp/sources.py
+++ b/tldp/sources.py
@@ -4,6 +4,7 @@ from __future__ import absolute_import, division, print_function
 
 import os
 import sys
+import operator
 
 from .utils import logger
 from .guess import guess, knownextensions
@@ -20,6 +21,7 @@ class Sources(object):
         self.docs = list()
         self.validateDirs()
         self.enumerateDocuments()
+        self.docs.sort(key=operator.attrgetter('stem'))
 
     def validateDirs(self):
         results = [os.path.exists(x) for x in self.sourcedirs]