diff --git a/test/runner.html b/test/runner.html
index e174cab993..2803f11adc 100644
--- a/test/runner.html
+++ b/test/runner.html
@@ -102,30 +102,12 @@
       return previous + (previous ? '&' : '') + next;
     }
 
-    // test shadowdom/custom elements polyfills together
-    // preferring both if possible.
     let flags = [''];
-    if (window.customElements) {
-      // NOTE: disabled because Native ShadowDOM and Polyfilled CustomElements is not an expected use-case.
-      // flags.push('wc-ce=true');
-    }
     // if native is available, make sure to test polyfill
     if (Element.prototype.attachShadow && Node.prototype.getRootNode) {
       flags.push('wc-shadydom=true');
     }
-    // Both sd and ce are supported, force both polyfills
-    if (flags.length === 2) {
-      // ce + sd becomes a single test iteration.
-      flags.push('wc-ce=true&wc-shadydom=true');
-    }
 
-    // economize testing by testing css shimming
-    // only against 1 environment (native or polyfill).
-    if (window.CSS && CSS.supports && CSS.supports('box-shadow', '0 0 0 var(--foo)')) {
-      // Note: Disabled to speed up testing, may be reenabled at a later date when the test timing is less of an issue.
-      // let last = flags.length === 1 ? '' : flags[flags.length - 1];
-      // flags.push(addUrlOption(last, 'wc-shimcssproperties=true'));
-    }
     suites = combinations(suites, flags);
     console.log('Testing suites:\n\t' + suites.join('\n\t'));