diff --git a/devtools/client/responsive.html/test/browser/browser_device_modal_exit.js b/devtools/client/responsive.html/test/browser/browser_device_modal_exit.js
index de90e522f966..68cf6f61f9aa 100644
--- a/devtools/client/responsive.html/test/browser/browser_device_modal_exit.js
+++ b/devtools/client/responsive.html/test/browser/browser_device_modal_exit.js
@@ -28,7 +28,7 @@ addRDMTask(TEST_URL, function* ({ ui }) {
   uncheckedCb.click();
   closeButton.click();
 
-  ok(modal.classList.contains("hidden"),
+  ok(modal.classList.contains("closed") && !modal.classList.contains("opened"),
     "The device modal is hidden on exit.");
 
   info("Check that the device list remains unchanged after exitting.");
diff --git a/devtools/client/responsive.html/test/browser/browser_device_modal_submit.js b/devtools/client/responsive.html/test/browser/browser_device_modal_submit.js
index 4078340cae04..184822f03fa0 100644
--- a/devtools/client/responsive.html/test/browser/browser_device_modal_submit.js
+++ b/devtools/client/responsive.html/test/browser/browser_device_modal_submit.js
@@ -61,7 +61,7 @@ addRDMTask(TEST_URL, function* ({ ui }) {
   uncheckedCb.click();
   submitButton.click();
 
-  ok(modal.classList.contains("hidden"),
+  ok(modal.classList.contains("closed") && !modal.classList.contains("opened"),
     "The device modal is hidden on submit.");
 
   info("Checking that the new device is added to the user preference list.");