diff --git a/.audit/oberstet_fix_1840.md b/.audit/oberstet_fix_1840.md
new file mode 100644
index 000000000..79d7c028a
--- /dev/null
+++ b/.audit/oberstet_fix_1840.md
@@ -0,0 +1,8 @@
+- [ ] I did **not** use any AI-assistance tools to help create this pull request.
+- [x] I **did** use AI-assistance tools to *help* create this pull request.
+- [x] I have read, understood and followed the projects' [AI Policy](https://github.com/crossbario/autobahn-python/blob/main/AI_POLICY.md) when creating code, documentation etc. for this pull request.
+
+Submitted by: @oberstet
+Date: 2026-07-01
+Related issue(s): #1840
+Branch: oberstet:fix_1840
diff --git a/docs/changelog.rst b/docs/changelog.rst
index 31610a383..ef11b2707 100644
--- a/docs/changelog.rst
+++ b/docs/changelog.rst
@@ -16,6 +16,7 @@ Changelog
 **Build & CI/CD**
 
 * Add CalVer / PEP 440 version-management ``just`` recipes (``file-version``, ``bump-dev``, ``bump-next``, ``prep-release``) mirroring Crossbar.io, and document the versioning policy in ``CONTRIBUTING.md`` (#1894)
+* Add ``ruff check --select ANN,UP,TCH`` (annotation presence, ``pyupgrade`` modern syntax, ``TYPE_CHECKING`` imports) to the ``just check-typing`` recipe so annotation/style regressions are caught in the ``quality-checks`` CI job. The existing gaps in ``src/autobahn/`` are ratcheted via an explicit ``--ignore`` allowlist to be removed module-by-module (#1839); all other ``UP``/``TC`` rules are enforced immediately, and generated code is excluded. The annotation rules are scoped to this recipe via the command line rather than the global ``[tool.ruff.lint]`` select, so the repo-wide ``check-format`` gate is unaffected (#1840)
 
 26.6.2
 ------
diff --git a/justfile b/justfile
index bcf3adae6..c47dd0bc9 100644
--- a/justfile
+++ b/justfile
@@ -730,7 +730,7 @@ check-format venv="": (install-tools venv)
 # Run static type checking with ty (Astral's Rust-based type checker)
 # FIXME: Many type errors need to be fixed. For now, we ignore most rules
 # to get CI passing. Create follow-up issue to address type errors.
-check-typing venv="": (install venv)
+check-typing venv="": (install venv) (install-tools venv)
     #!/usr/bin/env bash
     set -e
     VENV_NAME="{{ venv }}"
@@ -740,6 +740,20 @@ check-typing venv="": (install venv)
         echo "==> Defaulting to venv: '${VENV_NAME}'"
     fi
     VENV_PATH="{{ VENV_DIR }}/${VENV_NAME}"
+    echo "==> Checking type annotation presence and modern syntax (via ruff)..."
+    # Annotation presence (ANN), modern syntax (UP/pyupgrade) and TYPE_CHECKING
+    # imports (TC). The ANN/TC ignores below track the EXISTING gaps in src/autobahn/
+    # and should be removed module-by-module as typing improves (see #1839); every
+    # other UP and TC rule is enforced now, so new code cannot regress modern syntax.
+    # Generated code is skipped via the [tool.ruff] exclude list; --force-exclude makes
+    # that apply to the explicit src/autobahn/ path too.
+    "${VENV_PATH}/bin/ruff" check --select ANN,UP,TCH --force-exclude \
+        --ignore ANN001 --ignore ANN002 --ignore ANN003 \
+        --ignore ANN201 --ignore ANN202 --ignore ANN204 --ignore ANN205 --ignore ANN206 \
+        --ignore ANN401 \
+        --ignore UP037 \
+        --ignore TC001 --ignore TC002 --ignore TC003 \
+        src/autobahn/
     echo "==> Running static type checks with ty (using ${VENV_NAME} for type stubs)..."
     # Note: Only check src/autobahn/, not src/flatbuffers/ (generated code)
     # FIXME: Many ignores needed until type annotations are fixed
diff --git a/pyproject.toml b/pyproject.toml
index 9ed5f4f26..ac7acc00f 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -381,3 +381,10 @@ docstring-code-line-length = "dynamic"
 
 [tool.ruff.lint.pydocstyle]
 convention = "google"  # Accepts: "google", "numpy", or "pep257".
+
+# Shapes the flake8-annotations (ANN) rules that `just check-typing` selects on the
+# command line (see #1839). Inert for `check-format`, which does not select ANN.
+[tool.ruff.lint.flake8-annotations]
+mypy-init-return = true          # allow __init__ without an explicit -> None
+suppress-none-returning = false  # still require -> None on functions returning only None
+allow-star-arg-any = false       # *args/**kwargs must be typed, not implicitly Any