diff --git a/server.py b/server.py
index 63cd1a5565fcac535c507e4ebffeb49cf76ffde1..de234d1a1924bbfb16427e99a5c6c185f4050f6c 100755
--- a/server.py
+++ b/server.py
@@ -155,6 +155,7 @@ def rmfile(filename):
 
 def backup(corps, fname, old):
     """Backupe l'ancienne version du fichier"""
+    os.umask(0077)
     back = open(getpath(fname, backup=True), 'a')
     back.write(json.dumps(old))
     back.write('\n')