diff --git a/Cargo.toml b/Cargo.toml
index 031a13f..d4f1e97 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,7 +1,7 @@
 [package]
 name = "matrixmultiply"
 edition = "2018"
-version = "0.3.8"
+version = "0.3.9"
 authors = [
     "bluss",
     "R. Janis Goldschmidt"
diff --git a/README.rst b/README.rst
index a5579c0..640980c 100644
--- a/README.rst
+++ b/README.rst
@@ -51,6 +51,13 @@ __ https://bluss.github.io/rust/2016/03/28/a-gemmed-rabbit-hole/
 Recent Changes
 --------------
 
+- 0.3.9
+
+  - Fix debug assertion for alignment on s390x, involving alignment of the mask buffer;
+    the change lowered the static alignment request to (16) in thread local storage
+    on all platforms (except macos was unchanged).
+  - Test with cargo-careful
+
 - 0.3.8
 
   - Lower alignment requirement for thread local storage value on macos, since