diff --git a/src/url-pattern.ts b/src/url-pattern.ts
index 66867a8..673e600 100644
--- a/src/url-pattern.ts
+++ b/src/url-pattern.ts
@@ -340,6 +340,7 @@ export class URLPattern {
   #names: string[] = {};
   #component_pattern: any = {};
   #parts: any = {};
+  #hasRegExpGroups: boolean = false;
 
   constructor(init: URLPatternInit | string, baseURL?: string, options?: URLPatternOptions);
   constructor(init: URLPatternInit | string, options?: URLPatternOptions);
@@ -449,6 +450,8 @@ export class URLPattern {
           this.#parts[component] = parse(pattern as string, options);
           this.#regexp[component] = partsToRegexp(this.#parts[component], /* out */ this.#names[component], options);
           this.#component_pattern[component] = partsToPattern(this.#parts[component], options);
+          this.#hasRegExpGroups = this.#hasRegExpGroups ||
+                                  this.#parts[component].some((p: Part) => p.type === PartType.kRegex);
         } catch (err) {
           // If a pattern is illegal the constructor will throw an exception
           throw new TypeError(`invalid ${component} pattern '${this.#pattern[component]}'.`);
@@ -680,4 +683,8 @@ export class URLPattern {
   public get hash() {
     return this.#component_pattern.hash;
   }
+
+  public get hasRegExpGroups() {
+    return this.#hasRegExpGroups;
+  }
 }
diff --git a/test/urlpattern-hasregexpgroups-tests.js b/test/urlpattern-hasregexpgroups-tests.js
new file mode 100644
index 0000000..e8ddbe4
--- /dev/null
+++ b/test/urlpattern-hasregexpgroups-tests.js
@@ -0,0 +1,24 @@
+import test from "ava";
+import "urlpattern-polyfill";
+
+test("URLPattern.hasRegExpGroups", t => {
+  const assert_true = (actual, msg) => t.true(actual, msg);
+  const assert_false = (actual, msg) => t.false(actual, msg);
+
+  assert_true('hasRegExpGroups' in URLPattern.prototype, "hasRegExpGroups is not implemented");
+  assert_false(new URLPattern({}).hasRegExpGroups, "match-everything pattern");
+  for (let component of ['protocol', 'username', 'password', 'hostname', 'port', 'pathname', 'search', 'hash']) {
+    assert_false(new URLPattern({[component]: '*'}).hasRegExpGroups, `wildcard in ${component}`);
+    assert_false(new URLPattern({[component]: ':foo'}).hasRegExpGroups, `segment wildcard  in ${component}`);
+    assert_false(new URLPattern({[component]: ':foo?'}).hasRegExpGroups, `optional segment wildcard  in ${component}`);
+    assert_true(new URLPattern({[component]: ':foo(hi)'}).hasRegExpGroups, `named regexp group in ${component}`);
+    assert_true(new URLPattern({[component]: '(hi)'}).hasRegExpGroups, `anonymous regexp group in ${component}`);
+    if (component !== 'protocol' && component !== 'port') {
+      // These components are more narrow in what they accept in any case.
+      assert_false(new URLPattern({[component]: 'a-{:hello}-z-*-a'}).hasRegExpGroups, `wildcards mixed in with fixed text and wildcards in ${component}`);
+      assert_true(new URLPattern({[component]: 'a-(hi)-z-(lo)-a'}).hasRegExpGroups, `regexp groups mixed in with fixed text and wildcards in ${component}`);
+    }
+  }
+  assert_false(new URLPattern({pathname: '/a/:foo/:baz?/b/*'}).hasRegExpGroups, "complex pathname with no regexp");
+  assert_true(new URLPattern({pathname: '/a/:foo/:baz([a-z]+)?/b/*'}).hasRegExpGroups, "complex pathname with regexp");
+});
\ No newline at end of file