diff --git a/js/tests/visual/modal.html b/js/tests/visual/modal.html
index 13e93d154f..3c1e37cfda 100644
--- a/js/tests/visual/modal.html
+++ b/js/tests/visual/modal.html
@@ -221,7 +221,7 @@
       function reportFirefoxTestResult(result) {
         if (!firefoxTestDone) {
           ffBugTestResult.classList.add(result ? 'text-success' : 'text-danger')
-          ffBugTestResult.innerHTML = result ? 'PASS' : 'FAIL'
+          ffBugTestResult.textContent = result ? 'PASS' : 'FAIL'
         }
       }