diff --git a/test/src/gatherers/screenshots.js b/test/src/gatherers/screenshots.js
index 4b18c096a7c2..d5f293c6672a 100644
--- a/test/src/gatherers/screenshots.js
+++ b/test/src/gatherers/screenshots.js
@@ -24,6 +24,9 @@ let screenshotsGather = new ScreenshotsGather();
 describe('Screenshot gatherer', () => {
   it('returns an artifact for a real trace', () => {
     const traceData = require('../audits/performance/progressive-app.json');
+    // Currently this test must rely on knowing the phase hook for the gatherer.
+    // A little unfortunate, but we need a "run scheduler with this gatherer, this mocked driver,
+    // and this trace" test class to do that right
     return screenshotsGather.postProfiling(undefined, {traceContents: traceData}).then(_ => {
       assert.ok(Array.isArray(screenshotsGather.artifact));
       assert.equal(screenshotsGather.artifact.length, 7);