diff --git a/crates/webidl-tests/simple.js b/crates/webidl-tests/simple.js
index 2f6b3876..7dbd45b4 100644
--- a/crates/webidl-tests/simple.js
+++ b/crates/webidl-tests/simple.js
@@ -93,6 +93,20 @@ global.GlobalMethod = class GlobalMethod {
   }
 };
 
+global.Indexing = function () {
+  return new Proxy({}, {
+    get(obj, prop) {
+      return obj.hasOwnProperty(prop) ? obj[prop] : -1;
+    },
+    set(obj, prop, value) {
+      obj[prop] = value;
+    },
+    deleteProperty(obj, prop) {
+      delete obj[prop];
+    },
+  });
+};
+
 global.PartialInterface = class PartialInterface {
   get un() {
     return 1;
diff --git a/crates/webidl-tests/simple.rs b/crates/webidl-tests/simple.rs
index 914643be..1230bfbc 100644
--- a/crates/webidl-tests/simple.rs
+++ b/crates/webidl-tests/simple.rs
@@ -65,7 +65,17 @@ fn optional_method() {
 #[wasm_bindgen_test]
 fn global_method() {
     let f = GlobalMethod::new().unwrap();
-    assert!(f.m() == 123);
+    assert_eq!(f.m(), 123);
+}
+
+#[wasm_bindgen_test]
+fn indexing() {
+    let f = Indexing::new().unwrap();
+    assert_eq!(f.get(123), -1);
+    f.set(123, 456);
+    assert_eq!(f.get(123), 456);
+    f.delete(123);
+    assert_eq!(f.get(123), -1);
 }
 
 #[wasm_bindgen_test]
diff --git a/crates/webidl-tests/simple.webidl b/crates/webidl-tests/simple.webidl
index 810aba0c..8435c024 100644
--- a/crates/webidl-tests/simple.webidl
+++ b/crates/webidl-tests/simple.webidl
@@ -40,6 +40,13 @@ interface GlobalMethod {
   octet m();
 };
 
+[Constructor()]
+interface Indexing {
+  getter short (unsigned long index);
+  setter void (unsigned long index, short value);
+  deleter void (unsigned long index);
+};
+
 [Constructor()]
 interface Unforgeable {
   [Unforgeable] readonly attribute short uno;