diff --git a/sdk/lib/_internal/wasm/lib/list.dart b/sdk/lib/_internal/wasm/lib/list.dart
index 33958240d30..857145ec848 100644
--- a/sdk/lib/_internal/wasm/lib/list.dart
+++ b/sdk/lib/_internal/wasm/lib/list.dart
@@ -18,6 +18,7 @@ abstract class _ListBase<E> extends ListBase<E> {
   _ListBase._withData(this._length, this._data);
 
   E operator [](int index) {
+    RangeError.checkValidIndex(index, this, "[]", _length);
     return unsafeCast(_data.read(index));
   }
 
@@ -51,6 +52,7 @@ abstract class _ModifiableList<E> extends _ListBase<E> {
       : super._withData(length, data);
 
   void operator []=(int index, E value) {
+    RangeError.checkValidIndex(index, this, "[]=", _length);
     _data.write(index, value);
   }