diff --git a/browser/extensions/e10srollout/bootstrap.js b/browser/extensions/e10srollout/bootstrap.js
index e009d92dffc4e..81aabfa2c8da9 100644
--- a/browser/extensions/e10srollout/bootstrap.js
+++ b/browser/extensions/e10srollout/bootstrap.js
@@ -56,7 +56,8 @@ function defineCohort() {
 
   let userOptedOut = optedOut();
   let userOptedIn = optedIn();
-  let disqualified = (Services.appinfo.multiprocessBlockPolicy != 0);
+  let disqualified = (Services.appinfo.multiprocessBlockPolicy != 0) ||
+                     isThereAnActiveExperiment();
   let testGroup = (getUserSample() < TEST_THRESHOLD[updateChannel]);
 
   if (userOptedOut) {
@@ -112,3 +113,7 @@ function optedOut() {
           Preferences.get(PREF_TOGGLE_E10S) == false);
 }
 
+function isThereAnActiveExperiment() {
+  let { Experiments } = Cu.import("resource:///modules/experiments/Experiments.jsm", {});
+  return (Experiments.instance().getActiveExperiment() !== null);
+}