diff --git a/lib/utils/resolve-url.js b/lib/utils/resolve-url.js
index ae5e5e2ad5..fa98841801 100644
--- a/lib/utils/resolve-url.js
+++ b/lib/utils/resolve-url.js
@@ -28,9 +28,6 @@ export function resolveUrl(url, baseURI) {
   if (url && ABS_URL.test(url)) {
     return url;
   }
-  if (url === '//') {
-    return url;
-  }
   // Lazy feature detection.
   if (workingURL === undefined) {
     workingURL = false;
@@ -46,7 +43,12 @@ export function resolveUrl(url, baseURI) {
     baseURI = document.baseURI || window.location.href;
   }
   if (workingURL) {
-    return (new URL(url, baseURI)).href;
+    try {
+      return (new URL(url, baseURI)).href;
+    } catch (e) {
+      // Bad url or baseURI structure. Do not attempt to resolve.
+      return url;
+    }
   }
   // Fallback to creating an anchor into a disconnected document.
   if (!resolveDoc) {