diff --git a/ext/url/01_urlpattern.js b/ext/url/01_urlpattern.js
index 0bba59cf0e6b34..58a6d6bce08725 100644
--- a/ext/url/01_urlpattern.js
+++ b/ext/url/01_urlpattern.js
@@ -349,7 +349,7 @@ class URLPattern {
           const groups = res.groups;
           for (let i = 0; i < groupList.length; ++i) {
             // TODO(lucacasonato): this is vulnerable to override mistake
-            groups[groupList[i]] = match[i + 1];
+            groups[groupList[i]] = match[i + 1] ?? ""; // TODO(@crowlKats): remove fallback for 2.0
           }
           break;
         }
diff --git a/tests/unit/urlpattern_test.ts b/tests/unit/urlpattern_test.ts
index 3c1fb0cf19a55f..65c2241737441f 100644
--- a/tests/unit/urlpattern_test.ts
+++ b/tests/unit/urlpattern_test.ts
@@ -63,3 +63,9 @@ Deno.test(function urlPatternWithPrototypePollution() {
     RegExp.prototype.exec = originalExec;
   }
 });
+
+Deno.test(function urlPatternEmptyFallback() {
+  const p = new URLPattern({ pathname: "/foo/bar{/:qaz}?" });
+  const match = p.exec("https://example.com/foo/bar");
+  assertEquals(match!.pathname.groups.qaz, "");
+});
diff --git a/tests/wpt/runner/expectation.json b/tests/wpt/runner/expectation.json
index f59806feae3127..68d93c2c6555ab 100644
--- a/tests/wpt/runner/expectation.json
+++ b/tests/wpt/runner/expectation.json
@@ -12915,8 +12915,18 @@
       "Component: hash Left: {\"hash\":\"a\"} Right: {\"hash\":\"b\"}"
     ],
     "urlpattern.any.html": [
+      "Pattern: [{\"pathname\":\"/foo/:bar?\"}] Inputs: [{\"pathname\":\"/foo\"}]",
+      "Pattern: [{\"pathname\":\"/foo/:bar*\"}] Inputs: [{\"pathname\":\"/foo\"}]",
+      "Pattern: [{\"pathname\":\"/foo/(.*)?\"}] Inputs: [{\"pathname\":\"/foo\"}]",
+      "Pattern: [{\"pathname\":\"/foo/*?\"}] Inputs: [{\"pathname\":\"/foo\"}]",
+      "Pattern: [{\"pathname\":\"/foo/(.*)*\"}] Inputs: [{\"pathname\":\"/foo\"}]",
+      "Pattern: [{\"pathname\":\"/foo/**\"}] Inputs: [{\"pathname\":\"/foo\"}]",
+      "Pattern: [\"https://(sub.)?example.com/foo\"] Inputs: [\"https://example.com/foo\"]",
+      "Pattern: [\"https://(sub(?:.))?example.com/foo\"] Inputs: [\"https://example.com/foo\"]",
+      "Pattern: [\"data\\\\:text/javascript,let x = 100/:tens?5;\"] Inputs: [\"data:text/javascript,let x = 100/5;\"]",
       "Pattern: [{\"hostname\":\"bad\\\\:hostname\"}] Inputs: undefined",
       "Pattern: [] Inputs: []",
+      "Pattern: [{\"pathname\":\"*{}**?\"}] Inputs: [{\"pathname\":\"foobar\"}]",
       "Pattern: [{\"pathname\":\"/foo/bar\"},{\"ignoreCase\":true}] Inputs: [{\"pathname\":\"/FOO/BAR\"}]",
       "Pattern: [\"https://example.com:8080/foo?bar#baz\",{\"ignoreCase\":true}] Inputs: [{\"pathname\":\"/FOO\",\"search\":\"BAR\",\"hash\":\"BAZ\",\"baseURL\":\"https://example.com:8080\"}]",
       "Pattern: [{\"pathname\":\"/([[a-z]--a])\"}] Inputs: [{\"pathname\":\"/a\"}]",
@@ -12925,8 +12935,18 @@
       "Pattern: [{\"pathname\":\"/([\\\\d&&[0-1]])\"}] Inputs: [{\"pathname\":\"/3\"}]"
     ],
     "urlpattern.any.worker.html": [
+      "Pattern: [{\"pathname\":\"/foo/:bar?\"}] Inputs: [{\"pathname\":\"/foo\"}]",
+      "Pattern: [{\"pathname\":\"/foo/:bar*\"}] Inputs: [{\"pathname\":\"/foo\"}]",
+      "Pattern: [{\"pathname\":\"/foo/(.*)?\"}] Inputs: [{\"pathname\":\"/foo\"}]",
+      "Pattern: [{\"pathname\":\"/foo/*?\"}] Inputs: [{\"pathname\":\"/foo\"}]",
+      "Pattern: [{\"pathname\":\"/foo/(.*)*\"}] Inputs: [{\"pathname\":\"/foo\"}]",
+      "Pattern: [{\"pathname\":\"/foo/**\"}] Inputs: [{\"pathname\":\"/foo\"}]",
+      "Pattern: [\"https://(sub.)?example.com/foo\"] Inputs: [\"https://example.com/foo\"]",
+      "Pattern: [\"https://(sub(?:.))?example.com/foo\"] Inputs: [\"https://example.com/foo\"]",
+      "Pattern: [\"data\\\\:text/javascript,let x = 100/:tens?5;\"] Inputs: [\"data:text/javascript,let x = 100/5;\"]",
       "Pattern: [{\"hostname\":\"bad\\\\:hostname\"}] Inputs: undefined",
       "Pattern: [] Inputs: []",
+      "Pattern: [{\"pathname\":\"*{}**?\"}] Inputs: [{\"pathname\":\"foobar\"}]",
       "Pattern: [{\"pathname\":\"/foo/bar\"},{\"ignoreCase\":true}] Inputs: [{\"pathname\":\"/FOO/BAR\"}]",
       "Pattern: [\"https://example.com:8080/foo?bar#baz\",{\"ignoreCase\":true}] Inputs: [{\"pathname\":\"/FOO\",\"search\":\"BAR\",\"hash\":\"BAZ\",\"baseURL\":\"https://example.com:8080\"}]",
       "Pattern: [{\"pathname\":\"/([[a-z]--a])\"}] Inputs: [{\"pathname\":\"/a\"}]",
@@ -12935,8 +12955,18 @@
       "Pattern: [{\"pathname\":\"/([\\\\d&&[0-1]])\"}] Inputs: [{\"pathname\":\"/3\"}]"
     ],
     "urlpattern.https.any.html": [
+      "Pattern: [{\"pathname\":\"/foo/:bar?\"}] Inputs: [{\"pathname\":\"/foo\"}]",
+      "Pattern: [{\"pathname\":\"/foo/:bar*\"}] Inputs: [{\"pathname\":\"/foo\"}]",
+      "Pattern: [{\"pathname\":\"/foo/(.*)?\"}] Inputs: [{\"pathname\":\"/foo\"}]",
+      "Pattern: [{\"pathname\":\"/foo/*?\"}] Inputs: [{\"pathname\":\"/foo\"}]",
+      "Pattern: [{\"pathname\":\"/foo/(.*)*\"}] Inputs: [{\"pathname\":\"/foo\"}]",
+      "Pattern: [{\"pathname\":\"/foo/**\"}] Inputs: [{\"pathname\":\"/foo\"}]",
+      "Pattern: [\"https://(sub.)?example.com/foo\"] Inputs: [\"https://example.com/foo\"]",
+      "Pattern: [\"https://(sub(?:.))?example.com/foo\"] Inputs: [\"https://example.com/foo\"]",
+      "Pattern: [\"data\\\\:text/javascript,let x = 100/:tens?5;\"] Inputs: [\"data:text/javascript,let x = 100/5;\"]",
       "Pattern: [{\"hostname\":\"bad\\\\:hostname\"}] Inputs: undefined",
       "Pattern: [] Inputs: []",
+      "Pattern: [{\"pathname\":\"*{}**?\"}] Inputs: [{\"pathname\":\"foobar\"}]",
       "Pattern: [{\"pathname\":\"/foo/bar\"},{\"ignoreCase\":true}] Inputs: [{\"pathname\":\"/FOO/BAR\"}]",
       "Pattern: [\"https://example.com:8080/foo?bar#baz\",{\"ignoreCase\":true}] Inputs: [{\"pathname\":\"/FOO\",\"search\":\"BAR\",\"hash\":\"BAZ\",\"baseURL\":\"https://example.com:8080\"}]",
       "Pattern: [{\"pathname\":\"/([[a-z]--a])\"}] Inputs: [{\"pathname\":\"/a\"}]",
@@ -12945,8 +12975,18 @@
       "Pattern: [{\"pathname\":\"/([\\\\d&&[0-1]])\"}] Inputs: [{\"pathname\":\"/3\"}]"
     ],
     "urlpattern.https.any.worker.html": [
+      "Pattern: [{\"pathname\":\"/foo/:bar?\"}] Inputs: [{\"pathname\":\"/foo\"}]",
+      "Pattern: [{\"pathname\":\"/foo/:bar*\"}] Inputs: [{\"pathname\":\"/foo\"}]",
+      "Pattern: [{\"pathname\":\"/foo/(.*)?\"}] Inputs: [{\"pathname\":\"/foo\"}]",
+      "Pattern: [{\"pathname\":\"/foo/*?\"}] Inputs: [{\"pathname\":\"/foo\"}]",
+      "Pattern: [{\"pathname\":\"/foo/(.*)*\"}] Inputs: [{\"pathname\":\"/foo\"}]",
+      "Pattern: [{\"pathname\":\"/foo/**\"}] Inputs: [{\"pathname\":\"/foo\"}]",
+      "Pattern: [\"https://(sub.)?example.com/foo\"] Inputs: [\"https://example.com/foo\"]",
+      "Pattern: [\"https://(sub(?:.))?example.com/foo\"] Inputs: [\"https://example.com/foo\"]",
+      "Pattern: [\"data\\\\:text/javascript,let x = 100/:tens?5;\"] Inputs: [\"data:text/javascript,let x = 100/5;\"]",
       "Pattern: [{\"hostname\":\"bad\\\\:hostname\"}] Inputs: undefined",
       "Pattern: [] Inputs: []",
+      "Pattern: [{\"pathname\":\"*{}**?\"}] Inputs: [{\"pathname\":\"foobar\"}]",
       "Pattern: [{\"pathname\":\"/foo/bar\"},{\"ignoreCase\":true}] Inputs: [{\"pathname\":\"/FOO/BAR\"}]",
       "Pattern: [\"https://example.com:8080/foo?bar#baz\",{\"ignoreCase\":true}] Inputs: [{\"pathname\":\"/FOO\",\"search\":\"BAR\",\"hash\":\"BAZ\",\"baseURL\":\"https://example.com:8080\"}]",
       "Pattern: [{\"pathname\":\"/([[a-z]--a])\"}] Inputs: [{\"pathname\":\"/a\"}]",