diff --git a/lib/Stream.php b/lib/ByteStream.php
similarity index 97%
rename from lib/Stream.php
rename to lib/ByteStream.php
index 499f578..c317dee 100644
--- a/lib/Stream.php
+++ b/lib/ByteStream.php
@@ -4,7 +4,7 @@ namespace Amp\Stream;
 
 use AsyncInterop\Promise;
 
-interface Stream {
+interface ByteStream {
     /**
      * Determines if the stream is readable.
      *
diff --git a/lib/MemoryStream.php b/lib/MemoryStream.php
index 357e59d..ff9c41a 100644
--- a/lib/MemoryStream.php
+++ b/lib/MemoryStream.php
@@ -10,7 +10,7 @@ use AsyncInterop\Promise;
  * the buffer. This class by itself is not particularly useful, but it can be extended to add functionality upon reading
  * or writing, as well as acting as an example of how stream classes can be implemented.
  */
-class MemoryStream implements Stream {
+class MemoryStream implements ByteStream {
     /** @var \Amp\Stream\Buffer */
     private $buffer;
     
diff --git a/lib/functions.php b/lib/functions.php
index 0c1748c..43c979f 100644
--- a/lib/functions.php
+++ b/lib/functions.php
@@ -13,13 +13,12 @@ if (\strlen('…') !== 3) {
 } // @codeCoverageIgnoreEnd
 
 /**
- * @param \Amp\Stream\Stream $source
- * @param \Amp\Stream\Stream $destination
+ * @param \Amp\Stream\ByteStream $source
+ * @param \Amp\Stream\ByteStream $destination
  * @param int|null $bytes
  *
  * @return \AsyncInterop\Promise
  */
-function pipe(Stream $source, Stream $destination, int $bytes = null): Promise {
     return new Coroutine(__doPipe($source, $destination, $bytes));
 }
 
@@ -43,4 +42,5 @@ function __doPipe(Stream $source, Stream $destination, int $bytes = null): \Gene
     } while ($source->isReadable() && $destination->isWritable());
     
     return $written;
+function pipe(ByteStream $source, ByteStream $destination, int $bytes = null): Promise {
 }