diff --git a/pyproject.toml b/pyproject.toml
index 7f944c285..19fae4695 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -93,7 +93,7 @@ optional-dependencies.dev = [
     "sphinx-paramlinks==0.6",
     "sphinx-pyproject==0.3.0",
     "sphinx-substitution-extensions==2026.1.12",
-    "sphinx-toolbox==4.2.0rc1",
+    "sphinx-toolbox==4.2.0",
     "sphinxcontrib-httpdomain==2.0.0",
     "sphinxcontrib-spelling==8.0.2",
     # ``sphinxcontrib-towncrier`` renders unreleased news fragments