diff --git a/client.js b/client.js
index cd84eb3..79724da 100644
--- a/client.js
+++ b/client.js
@@ -23,7 +23,7 @@ function getConnection(opts) {
         function retry() {
           setTimeout(function () {
             getConnection(opts).then(resolve, retry);
-          }, 100 + (Math.random() * 250));
+          }, 100 + (parseInt(require('crypto').randomBytes(2).toString('hex'), 16) % 250));
         }
 
         if (!opts.connect && ('ENOENT' === err.code || 'ECONNREFUSED' === err.code)) {
@@ -126,7 +126,7 @@ function create(opts) {
 
       if ('function' === typeof args[args.length - 1]) {
         // TODO if off, search for cb and derive id from previous onMessage
-        id = Math.random();
+        id = require('crypto').randomBytes(16).toString('hex');
         cb = args.pop();
       }
 
diff --git a/server.js b/server.js
index be089ac..9c754de 100644
--- a/server.js
+++ b/server.js
@@ -64,7 +64,7 @@ function createApp(server, options) {
       // you might use location.query.access_token to authenticate or share sessions
       // or ws.upgradeReq.headers.cookie (see http://stackoverflow.com/a/16395220/151312
 
-      ws.__session_id = location.query.session_id || Math.random();
+      ws.__session_id = location.query.session_id || require('crypto').randomBytes(16).toString('hex');
 
       ws.on('message', function (buffer) {
         var cmd;
diff --git a/test-cluster.js b/test-cluster.js
index d6b8ff7..5219fd3 100644
--- a/test-cluster.js
+++ b/test-cluster.js
@@ -1,8 +1,8 @@
 'use strict';
 
 var cluster = require('cluster');
-//var numCores = 2;
-var numCores = require('os').cpus().length;
+var numCores = 2;
+//var numCores = require('os').cpus().length;
 var id = (cluster.isMaster && '0' || cluster.worker.id).toString();
 
 function run() {
@@ -18,12 +18,27 @@ function run() {
 
       store.get('baz', function (err, data) {
         if (err) { console.error(err); return; }
-        console.log(id, 'should be null:', data);
+        if (null !== data) {
+          console.error(id, 'should be null:', data);
+        }
       });
 
       store.get('foo', function (err, data) {
         if (err) { console.error(err); return; }
-        console.log(id, 'should be bar:', data);
+        if ('bar' !== data) {
+          console.error(id, 'should be bar:', data);
+        }
+
+        store.set('quux', { message: 'hey' }, function (/*err*/) {
+          store.get('quux', function (err, data) {
+            if (err) { console.error(err); return; }
+            if (!data || 'hey' !== data.message) {
+              console.error(id, "should be { message: 'hey' }:", data);
+            } else {
+              console.log('Are there any errors above? If not, we passed!');
+            }
+          });
+        });
       });
     });
   });