diff --git a/CHANGELOG.md b/CHANGELOG.md
index 6a78408..ae74ebd 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,19 @@ the project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html
 
 ## [Unreleased]
 
+## [0.4.2] — 2026-06-08
+
+### Fixed
+
+- **`__version__` was hardcoded and stale** (`__init__.py`). It read `"0.2.0"`
+  regardless of the installed release, since nothing tied it to the version in
+  `pyproject.toml`. It is now derived from the installed distribution metadata
+  via `importlib.metadata.version("table-stitcher")`, so it always reflects the
+  actual release (falling back to `"0.0.0+unknown"` when run from an
+  uninstalled source tree). The release gate now also asserts
+  `__version__` matches the `pyproject.toml` version, so the two can't drift
+  again.
+
 ## [0.4.1] — 2026-06-08
 
 ### Fixed
diff --git a/pyproject.toml b/pyproject.toml
index 43d47a6..29bbd94 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -4,7 +4,7 @@ build-backend = "hatchling.build"
 
 [project]
 name = "table-stitcher"
-version = "0.4.1"
+version = "0.4.2"
 description = "Reassemble tables split across page boundaries in PDF extraction"
 readme = "README.md"
 license = "MIT"
diff --git a/scripts/release_gate.sh b/scripts/release_gate.sh
index a86d661..c3ffe65 100755
--- a/scripts/release_gate.sh
+++ b/scripts/release_gate.sh
@@ -69,15 +69,23 @@ else
 fi
 
 echo "==> Smoke-testing installed wheel outside checkout"
+EXPECTED_VERSION="$(grep -E '^version = ' pyproject.toml | head -1 | sed -E 's/.*"([^"]+)".*/\1/')"
+export EXPECTED_VERSION
 (
   cd "$TMP_ENV"
   "$TMP_ENV/venv/bin/python" - <<'PY'
+import os
 import pathlib
+
 import table_stitcher
 
 package_path = pathlib.Path(table_stitcher.__file__).resolve()
+expected = os.environ["EXPECTED_VERSION"]
 assert "site-packages" in str(package_path), package_path
 assert table_stitcher.__version__, "missing __version__"
+assert table_stitcher.__version__ == expected, (
+    f"__version__ {table_stitcher.__version__!r} != pyproject version {expected!r}"
+)
 assert callable(table_stitcher.stitch_tables)
 print(f"installed {table_stitcher.__version__} from {package_path}")
 PY
diff --git a/src/table_stitcher/__init__.py b/src/table_stitcher/__init__.py
index ddf066a..70e7037 100644
--- a/src/table_stitcher/__init__.py
+++ b/src/table_stitcher/__init__.py
@@ -24,13 +24,20 @@ def inject(self, doc, logical_tables): ...
 
 import logging
 import time
+from importlib.metadata import PackageNotFoundError
+from importlib.metadata import version as _pkg_version
 from typing import Any, Optional
 
 from .adapters.base import TableStitcherAdapter
 from .merger import merge_multipage_tables
 from .models import LogicalTable, MergeTrace, MultiPageConfig, TableMeta
 
-__version__ = "0.2.0"
+# Single source of truth: the installed distribution's version (from
+# pyproject.toml). Derived rather than hardcoded so it can never drift.
+try:
+    __version__ = _pkg_version("table-stitcher")
+except PackageNotFoundError:  # running from a source tree without an install
+    __version__ = "0.0.0+unknown"
 __all__ = [
     "stitch_tables",
     "extract_table_meta",