diff --git a/modules/cache.js b/modules/cache.js
index 39f9aff..5fb045f 100644
--- a/modules/cache.js
+++ b/modules/cache.js
@@ -67,6 +67,8 @@ exp.update_timestamp = function(uuid, hash) {
 exp.save_hash = function(uuid, hash) {
   logging.log(uuid + " cache: saving hash");
   var time = new Date().getTime();
+  // store uuid in lower case if not null
+  uuid = uuid && uuid.toLowerCase();
   redis.hmset(uuid, "h", hash, "t", time);
 };
 
diff --git a/routes/avatars.js b/routes/avatars.js
index 241e046..93f0d65 100644
--- a/routes/avatars.js
+++ b/routes/avatars.js
@@ -15,7 +15,7 @@ var human_status = {
 
 /* GET avatar request. */
 router.get("/:uuid.:ext?", function(req, res) {
-  var uuid = req.params.uuid;
+  var uuid = (req.params.uuid || "").toLowerCase();
   var size = parseInt(req.query.size) || config.default_size;
   var def = req.query.default;
   var helm = req.query.hasOwnProperty("helm");
diff --git a/routes/skins.js b/routes/skins.js
index 76f6340..1680cfa 100644
--- a/routes/skins.js
+++ b/routes/skins.js
@@ -8,7 +8,7 @@ var lwip = require("lwip");
 
 /* GET skin request. */
 router.get("/:uuid.:ext?", function(req, res) {
-  var uuid = req.params.uuid;
+  var uuid = (req.params.uuid || "").toLowerCase();
   var def = req.query.default;
   var start = new Date();
   var etag = null;