diff --git a/_metadata.py b/_metadata.py
index 5b9fa842..47996c72 100644
--- a/_metadata.py
+++ b/_metadata.py
@@ -1,2 +1,2 @@
-__extension_version__ = "0.44.0"
+__extension_version__ = "0.45.0"
 __extension_name__ = "pytket-qiskit"
diff --git a/docs/changelog.rst b/docs/changelog.rst
index 70b7ee80..021e4cd2 100644
--- a/docs/changelog.rst
+++ b/docs/changelog.rst
@@ -1,10 +1,10 @@
 Changelog
 ~~~~~~~~~
 
+0.45.0 (October 2023)
+---------------------
 
-Unreleased
-----------
-
+* Updated pytket version requirement to 1.21.
 * Implement crosstalk noise model for AerBackend.
 * Don't include ``SimplifyInitial`` in default passes; instead make it an option
   to ``process_circuits()``.
diff --git a/setup.py b/setup.py
index bd257b82..8f63b948 100644
--- a/setup.py
+++ b/setup.py
@@ -44,7 +44,7 @@
     packages=find_namespace_packages(include=["pytket.*"]),
     include_package_data=True,
     install_requires=[
-        "pytket ~= 1.19",
+        "pytket ~= 1.21",
         "qiskit ~= 0.44.0",
         "qiskit-ibm-runtime ~= 0.12.0",
         "qiskit-aer ~= 0.12.2",