diff --git a/Cargo.toml b/Cargo.toml
index 32a58f3..d80593d 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "thin-vec"
-version = "0.2.20"
+version = "0.2.21"
 authors = ["Aria Beingessner <a.beingessner@gmail.com>"]
 edition = "2024"
 rust-version = "1.85"
diff --git a/RELEASES.md b/RELEASES.md
index a42b368..a840fce 100644
--- a/RELEASES.md
+++ b/RELEASES.md
@@ -1,3 +1,9 @@
+# Version 0.2.21 (2026-10-08)
+
+ * When collecting into a ThinVec, pass the size hint to `with_capacity` (#99).
+ * Implement Index/IndexMut (#98).
+ * Update ZST docs.
+
 # Version 0.2.20 (2026-09-16)
 
  * Make const_new the default, and bump MSRV to 1.85. `const_new` feature is still available but does nothing.