diff --git a/lib/internal/webstreams/encoding.js b/lib/internal/webstreams/encoding.js
index b5533b4287b65a..9cfea36989a228 100644
--- a/lib/internal/webstreams/encoding.js
+++ b/lib/internal/webstreams/encoding.js
@@ -133,6 +133,9 @@ class TextDecoderStream {
     this.#handle = new TextDecoder(encoding, options);
     this.#transform = new TransformStream({
       transform: (chunk, controller) => {
+        if (chunk === undefined) {
+          throw new ERR_INVALID_THIS('TextDecoderStream');
+        }
         const value = this.#handle.decode(chunk, { stream: true });
         if (value)
           controller.enqueue(value);
diff --git a/test/wpt/status/encoding.json b/test/wpt/status/encoding.json
index e78a8b3c0791be..f9378d7195a2a7 100644
--- a/test/wpt/status/encoding.json
+++ b/test/wpt/status/encoding.json
@@ -66,13 +66,6 @@
   "streams/decode-utf8.any.js": {
     "requires": ["small-icu"]
   },
-  "streams/decode-bad-chunks.any.js": {
-    "fail": {
-      "expected": [
-        "chunk of type undefined should error the stream"
-      ]
-    }
-  },
   "streams/decode-non-utf8.any.js": {
     "requires": ["full-icu"]
   },