diff --git a/.github/scripts/check-release-notes.py b/.github/scripts/check-release-notes.py
new file mode 100755
index 0000000..c7333ef
--- /dev/null
+++ b/.github/scripts/check-release-notes.py
@@ -0,0 +1,56 @@
+#!/usr/bin/env python3
+"""Render the release notes header the way the workflow does, and check it.
+
+The v0.1.0 notes shipped with an empty ```bash block in them. It came from
+editing the heredoc by string substitution — inserting a closing fence, some
+prose and an opening fence directly above a closing fence that was already
+there. Nothing rendered the result before it was published.
+
+Markdown has no compiler, so this is the compiler: unbalanced fences and empty
+code blocks are the two failures that survive review by looking fine in a diff.
+"""
+
+import pathlib
+import sys
+
+WORKFLOW = pathlib.Path(".github/workflows/release.yml")
+START = "cat > header.md <<'EOF'\n"
+END = "\n          EOF\n"
+
+
+def main() -> int:
+    text = WORKFLOW.read_text()
+    if START not in text or END not in text:
+        print(f"{WORKFLOW}: no release-notes heredoc to check")
+        return 1
+
+    body = text.split(START, 1)[1].split(END, 1)[0]
+    # The heredoc is indented ten spaces inside the YAML.
+    header = "\n".join(
+        line[10:] if line.startswith(" " * 10) else line for line in body.split("\n")
+    )
+    header = header.replace("OWNER", "example").replace("TAG", "v0.0.0")
+
+    lines = header.split("\n")
+    fences = [n for n, line in enumerate(lines) if line.strip().startswith("```")]
+
+    problems = []
+    if len(fences) % 2:
+        problems.append(f"{len(fences)} code fences — unbalanced, so one block never closes")
+
+    for opened, closed in zip(fences[0::2], fences[1::2]):
+        if not [line for line in lines[opened + 1 : closed] if line.strip()]:
+            problems.append(f"empty code block at lines {opened + 1}-{closed + 1}")
+
+    if problems:
+        print("release notes would render wrong:")
+        for problem in problems:
+            print(f"  {problem}")
+        return 1
+
+    print(f"release notes: {len(fences) // 2} code blocks, all balanced and non-empty")
+    return 0
+
+
+if __name__ == "__main__":
+    sys.exit(main())
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 2a02e1b..8ade4f3 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -68,6 +68,12 @@ jobs:
           fi
           echo "README and CI agree on $WANT"
 
+      # The v0.1.0 notes shipped with an empty ```bash block, from editing the
+      # heredoc by string substitution and never rendering the result.
+      # Markdown has no compiler; this is the compiler.
+      - name: The release notes would render
+        run: python3 .github/scripts/check-release-notes.py
+
       - name: Host tests
         run: cargo test -p oxinit-unit -p oxinit-graph -p oxinit-service -p oxinit-cgroup -p oxinit-user -p oxinit-ipc -p oxinit-log -p oxinit-timer
 
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index f3a8106..e9d1893 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -130,9 +130,6 @@ jobs:
           `ghcr.io/OWNER/oxinit:demo` tracks `main` if you would rather have the
           latest.
 
-          ```bash
-          ```
-
           ### Install
 
           Download the tarball for your architecture below, check it, and put
diff --git a/ROADMAP.md b/ROADMAP.md
index e570fc7..ccdd6ce 100644
--- a/ROADMAP.md
+++ b/ROADMAP.md
@@ -1000,6 +1000,31 @@ and runs.
 The lesson is the same one the bug taught, applied to the fix: the reason to
 run the command is that reasoning about what it will do is not the same thing.
 
+### v0.1.0, and an empty code block in its notes
+
+The release workflow worked on its first run: both architectures' tarballs with
+checksums, the versioned image, and notes generated from the merged pull
+requests. Verified by downloading what was published rather than trusting what
+was built — both checksums match, and the binaries out of both tarballs report
+`0.1.0` under emulation.
+
+The notes shipped with an empty ```` ```bash ```` block in them, reported by
+the first person to read them.
+
+It came from editing the heredoc that writes those notes by string
+substitution: the insertion ended with an opening fence directly above a
+closing fence that was already there. The diff looked fine. Nothing rendered
+the result, and Markdown has no compiler to complain.
+
+So CI has one now. `.github/scripts/check-release-notes.py` renders the header
+the way the workflow does and fails on unbalanced fences or empty blocks —
+which are exactly the two mistakes that survive review by looking correct in a
+diff. The published v0.1.0 notes were edited in place.
+
+Third time in this project that the failure was *editing text without looking
+at the output*, and the second time it reached somebody. It is worth naming as
+a pattern rather than as three separate slips.
+
 ## Not doing, and why
 
 These were on the list. They are coming off it with a reason rather than