diff --git a/Cargo.toml b/Cargo.toml
index 8477bbd..ddd7af4 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "sluice"
-version = "0.4.0"
+version = "0.4.0-alpha.1"
 authors = ["Stephen M. Coakley <me@stephencoakley.com>"]
 edition = "2018"
 description = "Efficient ring buffer for byte buffers, FIFO queues, and SPSC channels"