diff --git a/.size-limit.js b/.size-limit.js
index 4100751f2c40..2d5baacbfd88 100644
--- a/.size-limit.js
+++ b/.size-limit.js
@@ -234,7 +234,7 @@ module.exports = [
     path: createCDNPath('bundle.min.js'),
     gzip: false,
     brotli: false,
-    limit: '83 KB',
+    limit: '83.5 KB',
   },
   {
     name: 'CDN Bundle (incl. Tracing) - uncompressed',
diff --git a/packages/core/src/integrations/conversationId.ts b/packages/core/src/integrations/conversationId.ts
index c11b587d3a71..445e3327419b 100644
--- a/packages/core/src/integrations/conversationId.ts
+++ b/packages/core/src/integrations/conversationId.ts
@@ -4,6 +4,7 @@ import { defineIntegration } from '../integration';
 import { GEN_AI_CONVERSATION_ID_ATTRIBUTE } from '../semanticAttributes';
 import type { IntegrationFn } from '../types-hoist/integration';
 import type { Span } from '../types-hoist/span';
+import { spanToJSON } from '../utils/spanUtils';
 
 const INTEGRATION_NAME = 'ConversationId';
 
@@ -18,6 +19,16 @@ const _conversationIdIntegration = (() => {
         const conversationId = scopeData.conversationId || isolationScopeData.conversationId;
 
         if (conversationId) {
+          const { op, data: attributes, description: name } = spanToJSON(span);
+
+          // Only apply conversation ID to gen_ai spans.
+          // We also check for Vercel AI spans (ai.operationId attribute or ai.* span name)
+          // because the Vercel AI integration sets the gen_ai.* op in its own spanStart handler
+          // which fires after this, so the op is not yet available at this point.
+          if (!op?.startsWith('gen_ai.') && !attributes['ai.operationId'] && !name?.startsWith('ai.')) {
+            return;
+          }
+
           span.setAttribute(GEN_AI_CONVERSATION_ID_ATTRIBUTE, conversationId);
         }
       });
diff --git a/packages/core/test/lib/integrations/conversationId.test.ts b/packages/core/test/lib/integrations/conversationId.test.ts
index e9ea9cc50d45..be69a1476e83 100644
--- a/packages/core/test/lib/integrations/conversationId.test.ts
+++ b/packages/core/test/lib/integrations/conversationId.test.ts
@@ -26,7 +26,7 @@ describe('ConversationId', () => {
   it('applies conversation ID from current scope to span', () => {
     getCurrentScope().setConversationId('conv_test_123');
 
-    startSpan({ name: 'test-span' }, span => {
+    startSpan({ name: 'test-span', op: 'gen_ai.chat' }, span => {
       const spanJSON = spanToJSON(span);
       expect(spanJSON.data[GEN_AI_CONVERSATION_ID_ATTRIBUTE]).toBe('conv_test_123');
     });
@@ -35,7 +35,7 @@ describe('ConversationId', () => {
   it('applies conversation ID from isolation scope when current scope does not have one', () => {
     getIsolationScope().setConversationId('conv_isolation_456');
 
-    startSpan({ name: 'test-span' }, span => {
+    startSpan({ name: 'test-span', op: 'gen_ai.chat' }, span => {
       const spanJSON = spanToJSON(span);
       expect(spanJSON.data[GEN_AI_CONVERSATION_ID_ATTRIBUTE]).toBe('conv_isolation_456');
     });
@@ -45,14 +45,14 @@ describe('ConversationId', () => {
     getCurrentScope().setConversationId('conv_current_789');
     getIsolationScope().setConversationId('conv_isolation_999');
 
-    startSpan({ name: 'test-span' }, span => {
+    startSpan({ name: 'test-span', op: 'gen_ai.chat' }, span => {
       const spanJSON = spanToJSON(span);
       expect(spanJSON.data[GEN_AI_CONVERSATION_ID_ATTRIBUTE]).toBe('conv_current_789');
     });
   });
 
   it('does not apply conversation ID when not set in scope', () => {
-    startSpan({ name: 'test-span' }, span => {
+    startSpan({ name: 'test-span', op: 'gen_ai.chat' }, span => {
       const spanJSON = spanToJSON(span);
       expect(spanJSON.data[GEN_AI_CONVERSATION_ID_ATTRIBUTE]).toBeUndefined();
     });
@@ -62,7 +62,7 @@ describe('ConversationId', () => {
     getCurrentScope().setConversationId('conv_test_123');
     getCurrentScope().setConversationId(null);
 
-    startSpan({ name: 'test-span' }, span => {
+    startSpan({ name: 'test-span', op: 'gen_ai.chat' }, span => {
       const spanJSON = spanToJSON(span);
       expect(spanJSON.data[GEN_AI_CONVERSATION_ID_ATTRIBUTE]).toBeUndefined();
     });
@@ -71,8 +71,8 @@ describe('ConversationId', () => {
   it('applies conversation ID to nested spans', () => {
     getCurrentScope().setConversationId('conv_nested_abc');
 
-    startSpan({ name: 'parent-span' }, () => {
-      startSpan({ name: 'child-span' }, childSpan => {
+    startSpan({ name: 'parent-span', op: 'gen_ai.invoke_agent' }, () => {
+      startSpan({ name: 'child-span', op: 'gen_ai.chat' }, childSpan => {
         const childJSON = spanToJSON(childSpan);
         expect(childJSON.data[GEN_AI_CONVERSATION_ID_ATTRIBUTE]).toBe('conv_nested_abc');
       });
@@ -85,6 +85,7 @@ describe('ConversationId', () => {
     startSpan(
       {
         name: 'test-span',
+        op: 'gen_ai.chat',
         attributes: {
           [GEN_AI_CONVERSATION_ID_ATTRIBUTE]: 'conv_explicit',
         },
@@ -95,4 +96,13 @@ describe('ConversationId', () => {
       },
     );
   });
+
+  it('does not apply conversation ID to non-gen_ai spans', () => {
+    getCurrentScope().setConversationId('conv_test_123');
+
+    startSpan({ name: 'db-query', op: 'db.query' }, span => {
+      const spanJSON = spanToJSON(span);
+      expect(spanJSON.data[GEN_AI_CONVERSATION_ID_ATTRIBUTE]).toBeUndefined();
+    });
+  });
 });