diff --git a/src/bytes.rs b/src/bytes.rs
index 88a8c8f..6572434 100644
--- a/src/bytes.rs
+++ b/src/bytes.rs
@@ -1405,6 +1405,12 @@ impl ops::Deref for BytesMut {
     }
 }
 
+impl AsMut<[u8]> for BytesMut {
+    fn as_mut(&mut self) -> &mut [u8] {
+        self.inner.as_mut()
+    }
+}
+
 impl ops::DerefMut for BytesMut {
     #[inline]
     fn deref_mut(&mut self) -> &mut [u8] {