diff --git a/src/setup.py b/src/setup.py
index 75d055d..d8344b0 100644
--- a/src/setup.py
+++ b/src/setup.py
@@ -129,6 +129,7 @@ def run_setup(
     cwd: Path | None = None,
     trusted: bool = True,
     last_seen_version: str | None = None,
+    current_version: str | None = None,
 ) -> SetupReport:
     root = cwd or Path(__file__).resolve().parent.parent
     prefetches = [
@@ -136,8 +137,13 @@ def run_setup(
         start_keychain_prefetch(),
         start_project_scan(root),
     ]
+    # When the package is not installed via pip (dev / source checkout),
+    # `_read_package_version()` returns '0.0.0' — which makes any non-trivial
+    # `last_seen_version` compare as "newer than current" and suppresses
+    # release notes. Allow callers (tests, dev runs) to override.
+    effective_version = current_version if current_version is not None else _read_package_version()
     release_notes_payload = check_for_release_notes(
-        current_version=_read_package_version(),
+        current_version=effective_version,
         last_seen_version=last_seen_version,
         cwd=root,
     )
diff --git a/tests/test_setup_runtime_checks.py b/tests/test_setup_runtime_checks.py
index 02de29a..c1b0350 100644
--- a/tests/test_setup_runtime_checks.py
+++ b/tests/test_setup_runtime_checks.py
@@ -44,7 +44,16 @@ def test_run_setup_reports_runtime_and_release_notes(self) -> None:
             (Path(tmp) / 'CHANGELOG.md').write_text(
                 '# Changelog\n\n## 9.9.9\n- big release\n', encoding='utf-8',
             )
-            report = run_setup(cwd=Path(tmp), trusted=True, last_seen_version='0.0.1')
+            # Override current_version because in a source checkout the
+            # installed package metadata reports 0.0.0, which would make
+            # last_seen_version='0.0.1' compare as already-current and
+            # suppress all release notes.
+            report = run_setup(
+                cwd=Path(tmp),
+                trusted=True,
+                last_seen_version='0.0.1',
+                current_version='9.9.9',
+            )
         self.assertIsInstance(report, SetupReport)
         self.assertGreaterEqual(len(report.runtime_checks), 3)
         self.assertIn('big release', report.release_notes)