diff --git a/Cargo.toml b/Cargo.toml
index 61a61ce..4dd9697 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "arrayvec"
-version = "0.4.9"
+version = "0.4.10"
 authors = ["bluss"]
 license = "MIT/Apache-2.0"
 
diff --git a/README.rst b/README.rst
index 29d3a2f..4af5330 100644
--- a/README.rst
+++ b/README.rst
@@ -22,6 +22,11 @@ __ https://docs.rs/arrayvec
 Recent Changes (arrayvec)
 -------------------------
 
+- 0.4.10
+
+  - Use ``repr(C)`` in the ``union`` version that was introduced in 0.4.9, to
+    allay some soundness concerns.
+
 - 0.4.9
 
   - Use ``union`` in the implementation on when this is detected to be supported