diff --git a/lib/_stream_readable.js b/lib/_stream_readable.js
index 8e38030da85..01d886e6cab 100644
--- a/lib/_stream_readable.js
+++ b/lib/_stream_readable.js
@@ -285,7 +285,7 @@ function chunkInvalid(state, chunk) {
       chunk !== undefined &&
       !state.objectMode) {
     er = new errors.TypeError('ERR_INVALID_ARG_TYPE',
-                              'chunk', 'string/Buffer/Uint8Array');
+                              'chunk', ['string', 'Buffer', 'Uint8Array']);
   }
   return er;
 }
diff --git a/lib/_stream_writable.js b/lib/_stream_writable.js
index 1735fafb5f3..02481739250 100644
--- a/lib/_stream_writable.js
+++ b/lib/_stream_writable.js
@@ -252,7 +252,8 @@ function validChunk(stream, state, chunk, cb) {
   } else if (typeof chunk !== 'string' &&
              chunk !== undefined &&
              !state.objectMode) {
-    er = new errors.TypeError('ERR_INVALID_ARG_TYPE', 'chunk', 'string/buffer');
+    er = new errors.TypeError('ERR_INVALID_ARG_TYPE', 'chunk',
+                              ['string', 'Buffer']);
   }
   if (er) {
     stream.emit('error', er);