diff --git a/addon-test-support/index.js b/addon-test-support/index.js
index 9fd9ed27..a5258ce4 100644
--- a/addon-test-support/index.js
+++ b/addon-test-support/index.js
@@ -89,13 +89,14 @@ export function setupTestContainer() {
   }
 
   let params = QUnit.urlParams;
-  let containerVisibility = params.nocontainer ? 'hidden' : 'visible';
 
   if (params.devmode || params.fullscreencontainer) {
-    testContainer.className = ' full-screen';
+    testContainer.classList.add('ember-testing-container-full-screen');
   }
 
-  testContainer.style.visibility = containerVisibility;
+  if (params.nocontainer) {
+    testContainer.classList.add('ember-testing-container-hidden');
+  }
 }
 
 /**
diff --git a/vendor/ember-qunit/test-container-styles.css b/vendor/ember-qunit/test-container-styles.css
index 64fb586e..f661279c 100644
--- a/vendor/ember-qunit/test-container-styles.css
+++ b/vendor/ember-qunit/test-container-styles.css
@@ -30,7 +30,7 @@
   transform: translateZ(0);
 }
 
-#ember-testing-container.full-screen {
+#ember-testing-container.ember-testing-container-full-screen {
   width: 100%;
   height: 100%;
   overflow: auto;
@@ -39,6 +39,11 @@
   right: 0;
 }
 
+#ember-testing-container.ember-testing-container-hidden {
+  opacity: 0;
+  pointer-events: none;
+}
+
 #ember-testing {
   width: 200%;
   height: 200%;
@@ -46,7 +51,7 @@
   transform-origin: top left;
 }
 
-.full-screen #ember-testing {
+.ember-testing-container-full-screen #ember-testing {
   position: absolute;
   width: 100%;
   height: 100%;