diff --git a/changelog.d/11233.misc b/changelog.d/11233.misc
new file mode 100644
index 0000000000000000000000000000000000000000..fdf9e5642e28362521e04f8da3c4769f1e024fe8
--- /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 220084a49d467ce92d804391ec8ad27f73de942c..345cff09c346b743f2bc15ef3cc410866ad7f73d 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",
     ]
 )