diff --git a/packages/github/__tests__/orchestration.test.ts b/packages/github/__tests__/orchestration.test.ts
index 3b851ddb..0bda82f0 100644
--- a/packages/github/__tests__/orchestration.test.ts
+++ b/packages/github/__tests__/orchestration.test.ts
@@ -59,6 +59,14 @@ describe('orchestration ID support', () => {
       process.env['ACTIONS_ORCHESTRATION_ID'] = '   '
       expect(getUserAgentWithOrchestrationId('my-app')).toBe('my-app')
     })
+
+    it('does not duplicate orchestration ID if already present in base', () => {
+      process.env['ACTIONS_ORCHESTRATION_ID'] = 'abc-123'
+      const alreadyTagged = 'my-app actions_orchestration_id/abc-123'
+      expect(getUserAgentWithOrchestrationId(alreadyTagged)).toBe(
+        alreadyTagged
+      )
+    })
   })
 
   describe('public re-export', () => {
@@ -110,5 +118,15 @@ describe('orchestration ID support', () => {
       const opts = getOctokitOptions('fake-token')
       expect(opts.userAgent).toBe('actions_orchestration_id/bad_chars_here_')
     })
+
+    it('does not duplicate orchestration ID when caller already applied it', () => {
+      process.env['ACTIONS_ORCHESTRATION_ID'] = 'test-orch-id'
+      const opts = getOctokitOptions('fake-token', {
+        userAgent: 'my-app actions_orchestration_id/test-orch-id'
+      })
+      expect(opts.userAgent).toBe(
+        'my-app actions_orchestration_id/test-orch-id'
+      )
+    })
   })
 })
diff --git a/packages/github/src/internal/utils.ts b/packages/github/src/internal/utils.ts
index 5ff4db52..03c5822a 100644
--- a/packages/github/src/internal/utils.ts
+++ b/packages/github/src/internal/utils.ts
@@ -49,8 +49,10 @@ export function getUserAgentWithOrchestrationId(
   const orchId = process.env['ACTIONS_ORCHESTRATION_ID']?.trim()
   if (orchId) {
     const sanitizedId = orchId.replace(/[^a-z0-9_.-]/gi, '_')
+    const tag = `actions_orchestration_id/${sanitizedId}`
+    if (baseUserAgent?.includes(tag)) return baseUserAgent
     const ua = baseUserAgent ? `${baseUserAgent} ` : ''
-    return `${ua}actions_orchestration_id/${sanitizedId}`
+    return `${ua}${tag}`
   }
   return baseUserAgent
 }