diff --git a/.changeset/eager-bears-wander.md b/.changeset/eager-bears-wander.md
new file mode 100644
index 000000000..32094114e
--- /dev/null
+++ b/.changeset/eager-bears-wander.md
@@ -0,0 +1,5 @@
+---
+type: Fixed
+pr: 2215
+---
+**`milestone_name` is no longer clobbered with a delimiter-led fragment** — getMilestoneInfo's `##` heading regex was unanchored, so it matched a heading quoted inside backticks in the Milestones bullet and wrote garbage like `— Active Milestone` over the curated milestone name on every phase transition. Now consults the 🚧 marker first, anchors the regex to line start, strips the leading delimiter, and widens the preserve guard so a bad derive keeps the existing name. (#2135)
diff --git a/src/roadmap-parser.cts b/src/roadmap-parser.cts
index b0236d065..33845d957 100644
--- a/src/roadmap-parser.cts
+++ b/src/roadmap-parser.cts
@@ -275,6 +275,19 @@ interface MilestoneInfo {
   name: string;
 }
 
+/**
+ * Strip a leading delimiter run (whitespace, em/en-dash, colon, hyphen) from a
+ * milestone-name capture. Markdown headings commonly take the shape
+ * `## vX.Y — Name` or `## vX.Y: Name`; the raw capture includes the delimiter
+ * because `.trim()` only removes whitespace, not punctuation. A name beginning
+ * with punctuation is a delimiter-led fragment, not the curated name (#2135).
+ * NOTE: do not strip `#` — a name beginning with `#` is a heading-parse failure
+ * that should stay loud rather than be silently cleaned.
+ */
+function stripLeadingDelimiter(s: string): string {
+  return s.replace(/^[\s—–:-]+/, '').trim();
+}
+
 function getMilestoneInfo(cwd: string): MilestoneInfo {
   try {
     const roadmap = platformReadSync(path.join(planningDir(cwd), 'ROADMAP.md'));
@@ -294,22 +307,34 @@ function getMilestoneInfo(cwd: string): MilestoneInfo {
 
     if (stateVersion) {
       const escapedVer = escapeRegex(stateVersion);
-      const headingMatch = roadmap.match(
-        new RegExp(`##[^\\n]*${escapedVer}[:\\s]+([^\\n(]+)`, 'i')
+
+      // #2135: consult the 🚧 name-bearing marker FIRST. It is the only construct
+      // guaranteed to carry the milestone's curated name adjacent to its version
+      // (the active-milestone bullet). A `##` heading is often nameless
+      // ("## vX.Y — Active Milestone") and, when unanchored, was matched
+      // spuriously on a copy quoted inside backticks in this very bullet.
+      const listMatch = roadmap.match(
+        new RegExp(`🚧\\s*\\*?\\*?${escapedVer}\\s+([^*\\n]+)`, 'i')
       );
-      if (headingMatch) {
-        if (!headingMatch[0].includes('✅')) {
-          return { version: stateVersion, name: headingMatch[1].trim() };
-        }
-      } else {
-        const listMatch = roadmap.match(
-          new RegExp(`🚧\\s*\\*?\\*?${escapedVer}\\s+([^*\\n]+)`, 'i')
-        );
-        if (listMatch) {
-          return { version: stateVersion, name: listMatch[1].trim() };
-        }
-        return { version: stateVersion, name: 'milestone' };
+      if (listMatch) {
+        const name = stripLeadingDelimiter(listMatch[1]);
+        if (name) return { version: stateVersion, name };
       }
+
+      // Fall back to the `##` heading — ANCHORED to line start (`^` + `m` flag)
+      // so a heading quoted inside backticks or prose mid-line can no longer
+      // match. Skip shipped (✅) headings.
+      const headingMatch = roadmap.match(
+        new RegExp(`^##[^\\n]*${escapedVer}[:\\s]+([^\\n(]+)`, 'im')
+      );
+      if (headingMatch && !headingMatch[0].includes('✅')) {
+        // Strip a leading delimiter — `.trim()` removes whitespace, not the
+        // em-dash/colon that conventionally separates version from name.
+        const name = stripLeadingDelimiter(headingMatch[1]);
+        if (name) return { version: stateVersion, name };
+      }
+
+      return { version: stateVersion, name: 'milestone' };
     }
 
     const inProgressMatch = roadmap.match(/🚧\s*\*\*v(\d+(?:\.\d+)+)\s+([^*]+)\*\*/);
diff --git a/src/state.cts b/src/state.cts
index 06b41be4f..b28faeb40 100644
--- a/src/state.cts
+++ b/src/state.cts
@@ -1573,8 +1573,18 @@ function syncStateFrontmatter(content: string, cwd: string | undefined): string
   // existing frontmatter already holds; only an empty derived value falls through
   // to this guard (the primary #905 preserve path below handles that).
   const MILESTONE_NAME_PLACEHOLDER = 'milestone';
+  // #2135: widen the preserve guard. A bad derive is not always the literal
+  // placeholder — getMilestoneInfo can return a delimiter-led fragment
+  // ("— Active Milestone") when the roadmap regex mis-binds. Preserve the
+  // existing curated name unless the derived value actually looks like a name:
+  // non-empty, not the placeholder, and not punctuation-led.
+  const derivedName = derivedFm['milestone_name'];
+  const derivedLooksLikeName = typeof derivedName === 'string'
+    && derivedName.length > 0
+    && derivedName !== MILESTONE_NAME_PLACEHOLDER
+    && !/^[\s—–:-]/.test(derivedName);
   if (
-    derivedFm['milestone_name'] === MILESTONE_NAME_PLACEHOLDER &&
+    !derivedLooksLikeName &&
     existingFm['milestone_name'] &&
     existingFm['milestone_name'] !== MILESTONE_NAME_PLACEHOLDER
   ) {
diff --git a/tests/roadmap-parser.test.cjs b/tests/roadmap-parser.test.cjs
index ef6789899..ec46fa630 100644
--- a/tests/roadmap-parser.test.cjs
+++ b/tests/roadmap-parser.test.cjs
@@ -396,6 +396,88 @@ describe('roadmap-parser: getMilestoneInfo', () => {
   });
 });
 
+// ─── getMilestoneInfo — #2135 milestone_name clobber ──────────────────────────
+// The `##` heading regex was unanchored (no `^`/`m`), so it matched a `##`
+// quoted mid-line inside a Milestones bullet and captured a delimiter-led
+// fragment into `milestone_name`. The fix: consult the 🚧 name-bearing marker
+// FIRST, anchor the `##` regex to line start, and strip a leading delimiter.
+
+describe('roadmap-parser: getMilestoneInfo #2135 — milestone_name clobber', () => {
+  let tmpDir;
+
+  beforeEach(() => { tmpDir = createTempProject(); });
+  afterEach(() => { cleanup(tmpDir); });
+
+  test('case A: 🚧 bullet quoting a nameless ## heading in backticks', () => {
+    writeState(tmpDir, { gsd_state_version: '1.0', milestone: 'v1.8' });
+    writeRoadmap(tmpDir, [
+      '# Roadmap',
+      '',
+      '## Milestones',
+      '',
+      '- 🚧 **v1.8 user session cleanup** — Phases 36-41 — see `## v1.8 — Active Milestone` below',
+      '',
+      '## v1.8 — Active Milestone',
+      '',
+      '### Phase 36: Something',
+    ].join('\n'));
+    const info = getMilestoneInfo(tmpDir);
+    assert.strictEqual(info.version, 'v1.8');
+    assert.strictEqual(info.name, 'user session cleanup');
+  });
+
+  test('case B: nameless ## heading + 🚧 marker carries the real name', () => {
+    writeState(tmpDir, { gsd_state_version: '1.0', milestone: 'v1.9' });
+    writeRoadmap(tmpDir, [
+      '## v1.9 — Active Milestone',
+      '',
+      '### 🚧 v1.9 — Falsifiability',
+      '',
+      '### Phase 1: Hypothesis',
+    ].join('\n'));
+    const info = getMilestoneInfo(tmpDir);
+    assert.strictEqual(info.version, 'v1.9');
+    assert.strictEqual(info.name, 'Falsifiability');
+  });
+
+  test('case C: canonical ## vX.Y: Name (no regression)', () => {
+    writeState(tmpDir, { gsd_state_version: '1.0', milestone: 'v2.0' });
+    writeRoadmap(tmpDir, '## v2.0: The Big Launch\n### Phase 1: Setup\n');
+    const info = getMilestoneInfo(tmpDir);
+    assert.strictEqual(info.version, 'v2.0');
+    assert.strictEqual(info.name, 'The Big Launch');
+  });
+
+  test('case D: canonical ## vX.Y — Name (em-dash delimiter stripped)', () => {
+    writeState(tmpDir, { gsd_state_version: '1.0', milestone: 'v2.5' });
+    writeRoadmap(tmpDir, '## v2.5 — Galaxy Release\n### Phase 1: Start\n');
+    const info = getMilestoneInfo(tmpDir);
+    assert.strictEqual(info.version, 'v2.5');
+    assert.strictEqual(info.name, 'Galaxy Release');
+  });
+
+  test('case E: 🚧 bullet only, no ## heading (no regression)', () => {
+    writeState(tmpDir, { gsd_state_version: '1.0', milestone: 'v1.5' });
+    writeRoadmap(tmpDir, 'Some intro text.\n\n- 🚧 **v1.5 Quick Fix** — minor\n');
+    const info = getMilestoneInfo(tmpDir);
+    assert.strictEqual(info.version, 'v1.5');
+    assert.strictEqual(info.name, 'Quick Fix');
+  });
+
+  test('anchored regex never matches a ## heading quoted inside backticks mid-line', () => {
+    writeState(tmpDir, { gsd_state_version: '1.0', milestone: 'v3.0' });
+    writeRoadmap(tmpDir, [
+      '# Roadmap',
+      '',
+      'See `## v3.0 — Active Milestone` referenced here.',
+      '',
+      '## v3.0: Real Name',
+    ].join('\n'));
+    const info = getMilestoneInfo(tmpDir);
+    assert.strictEqual(info.name, 'Real Name');
+  });
+});
+
 // ─── getMilestonePhaseFilter ──────────────────────────────────────────────────
 
 describe('roadmap-parser: getMilestonePhaseFilter', () => {