diff --git a/src/__tests__/client.test.ts b/src/__tests__/client.test.ts
index 55611e1..108c669 100644
--- a/src/__tests__/client.test.ts
+++ b/src/__tests__/client.test.ts
@@ -66,4 +66,13 @@ describe('detectRuleIndex', () => {
     expect(detectRuleIndex('[AI_REVIEW:1]', 'ai_review')).toBe(0);
     expect(detectRuleIndex('[SECURITY_FIX:2]', 'security_fix')).toBe(1);
   });
+
+  it('should detect last occurrence when multiple tags exist', () => {
+    const content = 'Previous: [AI_REVIEW:1]\n\nActual result:\n[AI_REVIEW:2]';
+    expect(detectRuleIndex(content, 'ai_review')).toBe(1);
+  });
+
+  it('should detect last match with multiple occurrences', () => {
+    expect(detectRuleIndex('[PLAN:1] then [PLAN:2] finally [PLAN:3]', 'plan')).toBe(2);
+  });
 });
diff --git a/src/claude/client.ts b/src/claude/client.ts
index f37a19c..66e5de0 100644
--- a/src/claude/client.ts
+++ b/src/claude/client.ts
@@ -43,8 +43,9 @@ export interface ClaudeCallOptions {
  */
 export function detectRuleIndex(content: string, stepName: string): number {
   const tag = stepName.toUpperCase();
-  const regex = new RegExp(`\\[${tag}:(\\d+)\\]`, 'i');
-  const match = content.match(regex);
+  const regex = new RegExp(`\\[${tag}:(\\d+)\\]`, 'gi');
+  const matches = [...content.matchAll(regex)];
+  const match = matches.at(-1);
   if (match?.[1]) {
     const index = Number.parseInt(match[1], 10) - 1;
     return index >= 0 ? index : -1;