diff --git a/src/session.js b/src/session.js
index e1d0daf7fe..80e3225f1f 100644
--- a/src/session.js
+++ b/src/session.js
@@ -35,13 +35,18 @@ module.exports = class RiotSession {
         this.log = new Logger(this.username);
     }
 
-    static async create(username, puppeteerOptions, riotserver, hsUrl) {
+    static async create(username, puppeteerOptions, riotserver, hsUrl, throttleCpuFactor = 1) {
         const browser = await puppeteer.launch(puppeteerOptions);
         const page = await browser.newPage();
         await page.setViewport({
             width: 1280,
             height: 800
         });
+        if (throttleCpuFactor !== 1) {
+            const client = await page.target().createCDPSession();
+            console.log("throttling cpu by a factor of", throttleCpuFactor);
+            await client.send('Emulation.setCPUThrottlingRate', { rate: throttleCpuFactor });
+        }
         return new RiotSession(browser, page, username, riotserver, hsUrl);
     }
 
diff --git a/start.js b/start.js
index 43988095f9..b98dc7f366 100644
--- a/start.js
+++ b/start.js
@@ -25,8 +25,9 @@ program
     .option('--no-logs', "don't output logs, document html on error", false)
     .option('--riot-url [url]', "riot url to test", "http://localhost:5000")
     .option('--windowed', "dont run tests headless", false)
-    .option('--slow-mo', "run tests slower to follow whats going on", false)
+    .option('--slow-mo', "type at a human speed", false)
     .option('--dev-tools', "open chrome devtools in browser window", false)
+    .option('--throttle-cpu [factor]', "factor to slow down the cpu with", parseFloat, 1.0)
     .option('--no-sandbox', "same as puppeteer arg", false)
     .option('--log-directory <dir>', 'a directory to dump html and network logs in when the tests fail')
     .parse(process.argv);
@@ -57,7 +58,7 @@ async function runTests() {
     );
 
     async function createSession(username) {
-        const session = await RiotSession.create(username, options, program.riotUrl, hsUrl);
+        const session = await RiotSession.create(username, options, program.riotUrl, hsUrl, program.throttleCpu);
         sessions.push(session);
         return session;
     }