diff --git a/init.lua b/init.lua
index d4efe1f..6993e53 100644
--- a/init.lua
+++ b/init.lua
@@ -8,6 +8,10 @@
 -- another.
 --
 
+-- Path of the configuration
+conf_path = "/etc/ssowat/conf.json"
+log_file = "/var/log/nginx/ssowat.log"
+
 -- Remove prepending '@' & trailing 'init.lua'
 script_path = string.sub(debug.getinfo(1).source, 2, -9)
 
@@ -23,6 +27,11 @@ local socket = require "socket"
 local config = require "config"
 lustache = require "lustache"
 
+-- Make sure the log file exists and we can write in it
+io.popen("touch "..log_file)
+io.popen("chown www-data "..log_file)
+io.popen("chmod u+w "..log_file)
+
 -- Persistent shared table
 flashs = {}
 i18n = {}
@@ -54,8 +63,5 @@ for file in lfs.dir(locale_dir) do
     end
 end 
 
--- Path of the configuration
-conf_path = "/etc/ssowat/conf.json"
-
 -- You should see that in your Nginx error logs by default
 ngx.log(ngx.INFO, "SSOwat ready")