diff --git a/.github/workflows/external-links.yml b/.github/workflows/external-links.yml
index bbefa80..cc1f38b 100644
--- a/.github/workflows/external-links.yml
+++ b/.github/workflows/external-links.yml
@@ -50,25 +50,19 @@ jobs:
           set -euo pipefail
           python3 - <<'PY'
           import json, os
+          from scripts.check_external_links import render_issue_body, report_needs_issue
           report = json.load(open(os.environ["RUNNER_TEMP"] + "/report.json"))
-          lines = [f"The weekly external link check found {len(report['broken'])} broken link(s) among {report['checked']} checked "
-                   f"({len(report['unknown'])} more could not be verified: blocked, rate limited or unreachable; "
-                   f"{len(report['ignored'])} listed in `scripts/external-links-ignore.txt` were skipped).", ""]
-          for item in report["broken"]:
-              lines.append(f"- `{item['detail']}` {item['url']} (in {', '.join('`' + f + '`' for f in item['files'][:5])})")
-          lines += ["", "Find the current address of each source (or replace it), run `make build-explainers`, and this issue closes "
-                    "itself on the next weekly run once nothing is broken. Reproduce locally with `python3 scripts/check_external_links.py`."]
-          open(os.environ["RUNNER_TEMP"] + "/body.md", "w").write("\n".join(lines) + "\n")
-          open(os.environ["RUNNER_TEMP"] + "/broken_count", "w").write(str(len(report["broken"])))
+          open(os.environ["RUNNER_TEMP"] + "/body.md", "w").write(render_issue_body(report))
+          open(os.environ["RUNNER_TEMP"] + "/report_needs_issue", "w").write("1" if report_needs_issue(report) else "0")
           PY
           existing="$(gh issue list --repo "$GITHUB_REPOSITORY" --state open --search "\"$ISSUE_TITLE\" in:title" --json number,title -q ".[] | select(.title == \"$ISSUE_TITLE\") | .number" | head -n 1)"
-          broken="$(cat "$RUNNER_TEMP/broken_count")"
-          if [ "$broken" -gt 0 ]; then
+          report_needs_issue="$(cat "$RUNNER_TEMP/report_needs_issue")"
+          if [ "$report_needs_issue" = "1" ]; then
             if [ -n "$existing" ]; then
               gh issue edit "$existing" --repo "$GITHUB_REPOSITORY" --body-file "$RUNNER_TEMP/body.md"
             else
               gh issue create --repo "$GITHUB_REPOSITORY" --title "$ISSUE_TITLE" --label documentation --body-file "$RUNNER_TEMP/body.md"
             fi
           elif [ -n "$existing" ]; then
-            gh issue close "$existing" --repo "$GITHUB_REPOSITORY" --reason completed --comment "The weekly check found no broken external links."
+            gh issue close "$existing" --repo "$GITHUB_REPOSITORY" --reason completed --comment "The weekly check found no broken links or stale ignore entries."
           fi
diff --git a/scripts/check_external_links.py b/scripts/check_external_links.py
index 74e73d3..92a961b 100644
--- a/scripts/check_external_links.py
+++ b/scripts/check_external_links.py
@@ -180,16 +180,19 @@ def run(urls: dict[str, list[str]], limit: int | None = None, workers: int = 8,
         ignore: dict[str, str] | None = None) -> dict:
     ignore = ignore or {}
     ignored = [{"url": url, "reason": ignore[url], "files": urls[url]} for url in sorted(urls) if url in ignore]
+    stale_ignored = [{"url": url, "reason": reason} for url, reason in sorted(ignore.items()) if url not in urls]
     urls = {url: files for url, files in urls.items() if url not in ignore}
     items = sorted(urls)[:limit] if limit else sorted(urls)
     results = {"ok": [], "broken": [], "unknown": []}
     with concurrent.futures.ThreadPoolExecutor(workers) as pool:
         for url, (kind, detail) in zip(items, pool.map(lambda u: check_url(u, timeout), items)):
             results[kind].append({"url": url, "detail": detail, "files": urls[url]})
-    return {"checked": len(items), **{kind: results[kind] for kind in results}, "ignored": ignored}
+    return {"checked": len(items), **{kind: results[kind] for kind in results},
+            "ignored": ignored, "stale_ignored": stale_ignored}
 
 
 def render(report: dict) -> str:
+    stale_ignored = report.get("stale_ignored", [])
     lines = [f"Checked {report['checked']} external links: {len(report['ok'])} ok, "
              f"{len(report['broken'])} broken, {len(report['unknown'])} unknown."
              + (f" {len(report['ignored'])} ignored." if report.get("ignored") else "")]
@@ -201,9 +204,32 @@ def render(report: dict) -> str:
     if report.get("ignored"):
         lines += ["", "Ignored (listed in scripts/external-links-ignore.txt, not requested):"]
         lines += [f"  {item['url']}  ({item['reason']})" for item in report["ignored"]]
+    if stale_ignored:
+        lines += ["", f"Stale ignored URLs ({len(stale_ignored)} not found in checked documents):"]
+        lines += [f"  {item['url']}  ({item['reason']})" for item in stale_ignored]
     return "\n".join(lines)
 
 
+def render_issue_body(report: dict) -> str:
+    stale_count = len(report.get("stale_ignored", []))
+    stale_label = "entry" if stale_count == 1 else "entries"
+    lines = [f"The weekly external link check found {len(report['broken'])} broken link(s) among {report['checked']} checked "
+             f"({len(report['unknown'])} more could not be verified: blocked, rate limited or unreachable; "
+             f"{len(report['ignored'])} listed in `scripts/external-links-ignore.txt` were skipped). "
+             f"It also found {stale_count} stale ignore-list {stale_label} with no matching document.", ""]
+    for item in report["broken"]:
+        lines.append(f"- `{item['detail']}` {item['url']} (in {', '.join('`' + path + '`' for path in item['files'][:5])})")
+    lines += ["", "Fix any reported broken links and remove stale ignore-list entries, then run `make build-explainers`. "
+              "This issue closes itself on the next weekly run once both are clear. "
+              "Reproduce locally with `python3 scripts/check_external_links.py`."]
+    return "\n".join(lines) + "\n"
+
+
+def report_needs_issue(report: dict) -> bool:
+    """Keep the weekly issue open while broken links or stale ignores remain."""
+    return bool(report["broken"] or report.get("stale_ignored"))
+
+
 def main(argv=None) -> int:
     parser = argparse.ArgumentParser(description=__doc__.split("\n\n")[0])
     parser.add_argument("paths", nargs="*", type=Path, help="markdown files to check (default: explainers/*.md and the top-level docs)")
diff --git a/tests/test_check_external_links.py b/tests/test_check_external_links.py
index cf8849c..2d20d0f 100644
--- a/tests/test_check_external_links.py
+++ b/tests/test_check_external_links.py
@@ -156,21 +156,35 @@ def test_main_reports_without_failing_unless_asked(server, tmp_path, capsys):
     capsys.readouterr()
     assert script.main([str(doc), "--timeout", "5", "--json", "--limit", "2", "--check-local"]) == 0
     report = json.loads(capsys.readouterr().out)
-    assert report["checked"] == 2 and set(report) == {"checked", "ok", "broken", "unknown", "ignored"}
+    assert report["checked"] == 2 and set(report) == {
+        "checked", "ok", "broken", "unknown", "ignored", "stale_ignored"
+    }
 
 
 def test_ignore_list_skips_a_url_and_reports_it(server, tmp_path, capsys):
     doc = tmp_path / "doc.md"
     doc.write_text(f"[ok]({server}/ok) [gone]({server}/gone)\n", encoding="utf-8")
     ignore = tmp_path / "ignore.txt"
-    ignore.write_text(f"# a comment\n\n{server}/gone needs a login\n", encoding="utf-8")
+    ignore.write_text(f"# a comment\n\n{server}/gone needs a login\n{server}/retired no longer referenced\n", encoding="utf-8")
     assert script.main([str(doc), "--timeout", "5", "--check-local", "--ignore-file", str(ignore)]) == 0
     out = capsys.readouterr().out
     assert "0 broken" in out and "1 ignored" in out and "(needs a login)" in out
+    assert "Stale ignored URLs (1 not found in checked documents)" in out
+    assert f"{server}/retired  (no longer referenced)" in out
     assert script.main([str(doc), "--timeout", "5", "--check-local", "--json", "--ignore-file", str(ignore)]) == 0
     report = json.loads(capsys.readouterr().out)
     assert report["checked"] == 1 and [item["url"] for item in report["ignored"]] == [f"{server}/gone"]
     assert report["ignored"][0]["files"] == [str(doc)]
+    assert report["stale_ignored"] == [{"url": f"{server}/retired", "reason": "no longer referenced"}]
+    assert "1 stale ignore-list entry" in script.render_issue_body(report)
+    assert "remove stale ignore-list entries" in script.render_issue_body(report)
+    assert script.report_needs_issue(report)
+
+
+def test_weekly_issue_state_closes_only_when_broken_and_stale_lists_are_empty():
+    assert script.report_needs_issue({"broken": [], "stale_ignored": []}) is False
+    assert script.report_needs_issue({"broken": [{"url": "https://example.org/gone"}], "stale_ignored": []}) is True
+    assert script.report_needs_issue({"broken": [], "stale_ignored": [{"url": "https://example.org/old"}]}) is True
 
 
 def test_ignore_list_requires_a_reason_and_tolerates_a_missing_file(tmp_path):