diff --git a/README.md b/README.md
index 82a0321..62be52b 100644
--- a/README.md
+++ b/README.md
@@ -67,6 +67,8 @@ on "dev/testsession/start":
  * `mailer`: Subclass of `Mailer`, typically used to record emails instead of actually sending them.
  * `datetime`: Sets a simulated date used for all framework operations.
     Format as "yyyy-MM-dd HH:mm:ss" (Example: "2012-12-31 18:40:59").
+ * `globalTestSession`: Activate test session independently of the current browser session,
+    effectively setting the site into test session mode for all users. Only available in "dev" mode.
 
 Example usage with parameters:
 
diff --git a/code/TestSessionController.php b/code/TestSessionController.php
index 4334c41..275a94d 100644
--- a/code/TestSessionController.php
+++ b/code/TestSessionController.php
@@ -68,9 +68,13 @@ class TestSessionController extends Controller {
 	public function start() {
 		$params = $this->request->requestVars();
 
-		$generator = Injector::inst()->get('RandomGenerator');
-		$id = substr($generator->randomToken(), 0, 10);
-		Session::set('TestSessionId', $id);
+		if(!empty($params['globalTestSession'])) {
+			$id = null;
+		} else {
+			$generator = Injector::inst()->get('RandomGenerator');
+			$id = substr($generator->randomToken(), 0, 10);
+			Session::set('TestSessionId', $id);
+		}
 
 		// Convert datetime from form object into a single string
 		$params = $this->fixDatetimeFormField($params);
@@ -145,6 +149,12 @@ class TestSessionController extends Controller {
 				->setEmptyString('Empty database');
 		}
 		$fields->push(new CheckboxField('requireDefaultRecords', 'Create default data?'));
+		if(Director::isDev()) {
+			$fields->push(
+				CheckboxField::create('globalTestSession', 'Use global test session?')
+					->setDescription('Caution: Will apply to all users across browsers')
+			);
+		}
 		$fields->merge($this->getBaseFields());
 		$form = new Form(
 			$this,