diff --git a/lib/internal/streams/readable.js b/lib/internal/streams/readable.js
index aad4c594501ba6..caf41c3f424ace 100644
--- a/lib/internal/streams/readable.js
+++ b/lib/internal/streams/readable.js
@@ -260,7 +260,9 @@ function readableAddChunk(stream, chunk, encoding, addToFront) {
     } else if (chunk instanceof Buffer) {
       encoding = '';
     } else if (Stream._isUint8Array(chunk)) {
-      chunk = Stream._uint8ArrayToBuffer(chunk);
+      if (!state.decoder) {
+        chunk = Stream._uint8ArrayToBuffer(chunk);
+      }
       encoding = '';
     } else if (chunk != null) {
       err = new ERR_INVALID_ARG_TYPE(