diff --git a/changelog.d/11233.misc b/changelog.d/11233.misc
new file mode 100644
index 0000000000..fdf9e5642e
--- /dev/null
+++ b/changelog.d/11233.misc
@@ -0,0 +1 @@
+Add `twine` and `towncrier` as dev dependencies, as they're used by the release script.
diff --git a/setup.py b/setup.py
index 220084a49d..345cff09c3 100755
--- a/setup.py
+++ b/setup.py
@@ -132,6 +132,9 @@ CONDITIONAL_REQUIREMENTS["dev"] = (
         "GitPython==3.1.14",
         "commonmark==0.9.1",
         "pygithub==1.55",
+        # The following are executed as commands by the release script.
+        "twine",
+        "towncrier",
     ]
 )