diff --git a/doc/changelog.rst b/doc/changelog.rst
index 8dbaa74a..a400a6cb 100644
--- a/doc/changelog.rst
+++ b/doc/changelog.rst
@@ -9,6 +9,7 @@ Changelog
 - Fix compatibility with numpy 2.0.
 - Change the unit tests to allocate TCP and UDP ports dynamically.
 - Add a series of tutorials to the manual.
+- Add a missing type annotation for :py:meth:`spead2.ThreadPool.set_affinity`.
 - Add a Jenkins configuration to test the ibverbs support on a SARAO-internal
   Jenkins server.
 - Bump versions of dependencies used in CI.
diff --git a/meson.build b/meson.build
index 0bf09980..90953382 100644
--- a/meson.build
+++ b/meson.build
@@ -30,7 +30,7 @@ project(
     'b_staticpic=false',  # The default of true harms performance
   ]
 )
-shared_lib_version = '8.0.0'
+shared_lib_version = '9.0.0'
 
 compiler = meson.get_compiler('cpp')
 py = import('python').find_installation(pure : false, modules : ['jinja2', 'pycparser', 'packaging'])
diff --git a/src/spead2/__init__.pyi b/src/spead2/__init__.pyi
index 55d69e13..a22c183f 100644
--- a/src/spead2/__init__.pyi
+++ b/src/spead2/__init__.pyi
@@ -81,6 +81,8 @@ class ThreadPool:
     def __init__(self, threads: int = ...) -> None: ...
     @overload
     def __init__(self, threads: int, affinity: list[int]) -> None: ...
+    @staticmethod
+    def set_affinity(core: int) -> None: ...
 
 class MemoryAllocator:
     def __init__(self) -> None: ...