diff --git a/packages/cli/src/calibrate/match.test.ts b/packages/cli/src/calibrate/match.test.ts
index a11b95d..8e0952a 100644
--- a/packages/cli/src/calibrate/match.test.ts
+++ b/packages/cli/src/calibrate/match.test.ts
@@ -220,3 +220,59 @@ describe('matchClustersToGold — edge cases', () => {
     expect(outcomes.filter(o => o.kind === 'false_positive')).toHaveLength(1);
   });
 });
+
+describe('matchClustersToGold — normalizedMessage is a tiebreaker, not a hard gate', () => {
+  it('matches on kind + location even when normalizedMessage does not appear in output', () => {
+    // The bench gold authors normalizedMessage as a semantic label
+    // ("homepage-multiple-h1") that never appears verbatim in detector output.
+    // kind + location is sufficient to confirm the planted bug was found.
+    const cluster = makeCluster({
+      id: 'ck_seo', kind: 'seo_h1_missing_or_multiple', bugIdentity: 'seo0h10000000000',
+      signatureKey: 'unknown|seo_h1_missing_or_multiple|/|2',
+      rootCause: 'Page "/" has 2 <h1> element(s) — exactly 1 is required',
+    });
+    const gold = makeGold({
+      goldId: 'nb-h1', kind: 'seo_h1_missing_or_multiple', bugIdentity: undefined,
+      structuralMatch: { kind: 'seo_h1_missing_or_multiple', normalizedLocation: '/', normalizedMessage: 'homepage-multiple-h1' },
+    });
+    const { outcomes, ambiguities } = matchClustersToGold([cluster], [gold]);
+    expect(ambiguities).toEqual([]);
+    const tp = outcomes.find(o => o.kind === 'true_positive');
+    expect(tp).toBeDefined();
+    expect(tp && tp.kind === 'true_positive' ? tp.matchVia : undefined).toBe('structural');
+  });
+
+  it('does NOT match when the location genuinely differs', () => {
+    const cluster = makeCluster({
+      id: 'ck_rob', kind: 'seo_robots_blocking_crawl', bugIdentity: 'rob00000000000000',
+      signatureKey: 'unknown|seo_robots_blocking_crawl|/',
+      rootCause: 'robots.txt has "Disallow: /" for User-agent: *',
+    });
+    const gold = makeGold({
+      goldId: 'nb-rob', kind: 'seo_robots_blocking_crawl', bugIdentity: undefined,
+      structuralMatch: { kind: 'seo_robots_blocking_crawl', normalizedLocation: '/robots.txt', normalizedMessage: 'disallow-all' },
+    });
+    const { outcomes } = matchClustersToGold([cluster], [gold]);
+    expect(outcomes.find(o => o.kind === 'true_positive')).toBeUndefined();
+    expect(outcomes.find(o => o.kind === 'false_negative')).toBeDefined();
+  });
+
+  it('uses normalizedMessage to disambiguate multiple same-kind+location candidates', () => {
+    const c1 = makeCluster({ id: 'ck_a', kind: 'dom_error_text', bugIdentity: 'a000000000000000', signatureKey: 'x|dom_error_text|/page', rootCause: 'alpha error shown' });
+    const c2 = makeCluster({ id: 'ck_b', kind: 'dom_error_text', bugIdentity: 'b000000000000000', signatureKey: 'x|dom_error_text|/page', rootCause: 'beta error shown' });
+    const gold = makeGold({ goldId: 'g-dom', kind: 'dom_error_text', bugIdentity: undefined, structuralMatch: { kind: 'dom_error_text', normalizedLocation: '/page', normalizedMessage: 'beta' } });
+    const { outcomes, ambiguities } = matchClustersToGold([c1, c2], [gold]);
+    expect(ambiguities).toEqual([]);
+    const tp = outcomes.find(o => o.kind === 'true_positive');
+    expect(tp && tp.kind === 'true_positive' ? tp.clusterId : undefined).toBe('ck_b');
+  });
+
+  it('is ambiguous when multiple same-kind+location candidates cannot be disambiguated by message', () => {
+    const c1 = makeCluster({ id: 'ck_a', kind: 'dom_error_text', bugIdentity: 'a000000000000000', signatureKey: 'x|dom_error_text|/page', rootCause: 'alpha' });
+    const c2 = makeCluster({ id: 'ck_b', kind: 'dom_error_text', bugIdentity: 'b000000000000000', signatureKey: 'x|dom_error_text|/page', rootCause: 'beta' });
+    const gold = makeGold({ goldId: 'g-dom', kind: 'dom_error_text', bugIdentity: undefined, structuralMatch: { kind: 'dom_error_text', normalizedLocation: '/page', normalizedMessage: 'gamma-not-present' } });
+    const { ambiguities } = matchClustersToGold([c1, c2], [gold]);
+    expect(ambiguities.length).toBe(1);
+    expect(ambiguities[0].goldId).toBe('g-dom');
+  });
+});
diff --git a/packages/cli/src/calibrate/match.ts b/packages/cli/src/calibrate/match.ts
index 41cfc86..3f55eec 100644
--- a/packages/cli/src/calibrate/match.ts
+++ b/packages/cli/src/calibrate/match.ts
@@ -105,32 +105,50 @@ export function matchClustersToGold(
         continue;
       }
 
-      const candidates = (byStructural.get(entry.kind) ?? []).filter(c => {
+      // Primary structural signals: kind (index) + normalizedLocation. The gold's
+      // normalizedMessage is authored as a semantic label that rarely appears
+      // verbatim in detector output, so it is a TIEBREAKER among multiple
+      // same-kind+location candidates, not a hard gate. (A single kind+location
+      // candidate is accepted even if the message label does not align.)
+      const sameKindLoc = (byStructural.get(entry.kind) ?? []).filter(c => {
         if (consumedClusterIds.has(c.id)) return false;
-        // Match on normalizedLocation: compare against signatureKey
+        const sig = c.signatureKey ?? '';
+        return sig.includes(sm.normalizedLocation) || sm.normalizedLocation === '*';
+      });
+
+      const messageMatches = (c: BugCluster): boolean => {
         const sig = c.signatureKey ?? '';
         return (
-          sig.includes(sm.normalizedLocation) ||
-          sm.normalizedLocation === '*'
-        ) && (
           sig.includes(sm.normalizedMessage) ||
           c.rootCause.toLowerCase().includes(sm.normalizedMessage.toLowerCase()) ||
           sm.normalizedMessage === '*'
         );
-      });
+      };
+
+      let matched: BugCluster | undefined;
+      let ambiguousCandidates: BugCluster[] | undefined;
+      if (sameKindLoc.length === 1) {
+        matched = sameKindLoc[0];
+      } else if (sameKindLoc.length > 1) {
+        // Disambiguate by normalizedMessage; exactly one message-match wins.
+        // 0 or >1 message-matches among multiple location candidates is
+        // genuinely ambiguous — surface as fatal so the gold is tightened.
+        const msgMatched = sameKindLoc.filter(messageMatches);
+        if (msgMatched.length === 1) matched = msgMatched[0];
+        else ambiguousCandidates = sameKindLoc;
+      }
 
-      if (candidates.length === 1) {
-        const cluster = candidates[0];
+      if (matched !== undefined) {
         outcomes.push({
           kind: 'true_positive',
           goldId: entry.goldId,
-          clusterId: cluster.id,
+          clusterId: matched.id,
           matchVia: 'structural',
           bugKind: entry.kind,
         });
-        consumedClusterIds.add(cluster.id);
-      } else if (candidates.length > 1) {
-        ambiguities.push({ goldId: entry.goldId, candidates: candidates.map(c => c.id) });
+        consumedClusterIds.add(matched.id);
+      } else if (ambiguousCandidates !== undefined) {
+        ambiguities.push({ goldId: entry.goldId, candidates: ambiguousCandidates.map(c => c.id) });
         // Don't emit an outcome for ambiguous matches — caller handles as fatal
       } else if (entry.expected === 'detector_fires') {
         outcomes.push({