diff --git a/gfx/layers/apz/test/mochitest/browser_test_group_fission.js b/gfx/layers/apz/test/mochitest/browser_test_group_fission.js
index 7b5d39eac0ca..4e0cbda738ca 100644
--- a/gfx/layers/apz/test/mochitest/browser_test_group_fission.js
+++ b/gfx/layers/apz/test/mochitest/browser_test_group_fission.js
@@ -44,7 +44,6 @@ add_task(async function test_main() {
     { file: "helper_fission_large_subframe.html" },
     { file: "helper_fission_initial_displayport.html" },
     { file: "helper_fission_checkerboard_severity.html" },
-    { file: "helper_fission_setResolution.html" },
     { file: "helper_fission_inactivescroller_positionedcontent.html" },
     { file: "helper_fission_irregular_areas.html" },
     // add additional tests here
diff --git a/gfx/layers/apz/test/mochitest/helper_fission_setResolution.html b/gfx/layers/apz/test/mochitest/helper_fission_setResolution.html
index 6bcf3fa2ce6d..0980a930981a 100644
--- a/gfx/layers/apz/test/mochitest/helper_fission_setResolution.html
+++ b/gfx/layers/apz/test/mochitest/helper_fission_setResolution.html
@@ -9,51 +9,47 @@
   <script src="apz_test_utils.js"></script>
   <script>
 
-fission_subtest_init();
+    async function test() {
+      let iframeElement = document.getElementById("testframe");
 
-FissionTestHelper.startTestPromise
-  .then(waitUntilApzStable)
-  .then(loadOOPIFrame("testframe", "helper_fission_empty.html"))
-  .then(waitUntilApzStable)
-  .then(test)
-  .then(FissionTestHelper.subtestDone, FissionTestHelper.subtestFailed);
+      const scale = 2.0;
 
-async function test() {
-  let iframeElement = document.getElementById("testframe");
+      SpecialPowers.getDOMWindowUtils(window).setResolutionAndScaleTo(scale);
+      await promiseApzFlushedRepaints(window);
+      await waitUntilApzStable();
 
-  const scale = 2.0;
+      const originalWidth = originalHeight = 100;
+      // eslint-disable-next-line no-unused-vars
+      let { _x, _y, width, height } = await SpecialPowers.spawn(
+        iframeElement,
+        [originalWidth, originalHeight],
+        // eslint-disable-next-line no-shadow
+        (width, height) => {
+          // nsIDOMWindowUtils.toScreenRect uses the iframe's transform which should
+          // have been informed from APZ.
+          return SpecialPowers.DOMWindowUtils.toScreenRect(0, 0, width, height);
+        }
+      );
 
-  SpecialPowers.getDOMWindowUtils(window).setResolutionAndScaleTo(scale);
-  await promiseApzFlushedRepaints(window);
-  await waitUntilApzStable();
-
-  const originalWidth = originalHeight = 100;
-  // eslint-disable-next-line no-unused-vars
-  let { _x, _y, width, height } = await SpecialPowers.spawn(
-    iframeElement,
-    [originalWidth, originalHeight],
-    // eslint-disable-next-line no-shadow
-    (width, height) => {
-      // nsIDOMWindowUtils.toScreenRect uses the iframe's transform which should
-      // have been informed from APZ.
-      return SpecialPowers.DOMWindowUtils.toScreenRect(0, 0, width, height);
+      is(width, scale * originalWidth,
+        "The resolution value should be properly delivered into OOP iframes");
+      is(height, scale * originalHeight,
+        "The resolution value should be properly delivered into OOP iframes");
     }
-  );
 
-  is(width, scale * originalWidth,
-     "The resolution value should be properly delivered into OOP iframes");
-  is(height, scale * originalHeight,
-     "The resolution value should be properly delivered into OOP iframes");
-}
+    waitUntilApzStable()
+      .then(test)
+      .then(subtestDone, subtestFailed);
 
   </script>
   <style>
-    body, html {
-        margin: 0;
+    body,
+    html {
+      margin: 0;
     }
   </style>
 </head>
 <body>
-<iframe id="testframe"></iframe>
+  <iframe id="testframe"></iframe>
 </body>
 </html>
diff --git a/gfx/layers/apz/test/mochitest/test_group_fission.html b/gfx/layers/apz/test/mochitest/test_group_fission.html
index 293dae9cf684..a8135966fd2a 100644
--- a/gfx/layers/apz/test/mochitest/test_group_fission.html
+++ b/gfx/layers/apz/test/mochitest/test_group_fission.html
@@ -20,6 +20,7 @@
     ];
 
     var subtests = [
+      { "file": "helper_fission_setResolution.html", "prefs": prefs },
       {
         "file": "helper_fission_tap_on_zoomed.html",
         "prefs": [["apz.max_tap_time", 10000]],
