diff --git a/test/parallel/test-whatwg-encoding-custom-textdecoder.js b/test/parallel/test-whatwg-encoding-custom-textdecoder.js
index 0e0619a9348f9a..74c6a002223255 100644
--- a/test/parallel/test-whatwg-encoding-custom-textdecoder.js
+++ b/test/parallel/test-whatwg-encoding-custom-textdecoder.js
@@ -208,6 +208,6 @@ if (common.hasIntl) {
     assert.strictEqual(str, '\ufffd');
   } catch (e) {
     // Encoding may not be available, e.g. small-icu builds
-    assert(e.code, 'ERR_ENCODING_NOT_SUPPORTED');
+    assert.strictEqual(e.code, 'ERR_ENCODING_NOT_SUPPORTED');
   }
 }