diff --git a/apps/sim/app/api/copilot/chat/route.ts b/apps/sim/app/api/copilot/chat/route.ts
index 25349e914..500b7e1a6 100644
--- a/apps/sim/app/api/copilot/chat/route.ts
+++ b/apps/sim/app/api/copilot/chat/route.ts
@@ -85,7 +85,7 @@ const ChatMessageSchema = z.object({
   chatId: z.string().optional(),
   workflowId: z.string().optional(),
   workflowName: z.string().optional(),
-  model: z.string().optional().default('claude-opus-4-6'),
+  model: z.string().optional().default('claude-opus-4-5'),
   mode: z.enum(COPILOT_REQUEST_MODES).optional().default('agent'),
   prefetch: z.boolean().optional(),
   createNewChat: z.boolean().optional().default(false),
@@ -238,7 +238,7 @@ export async function POST(req: NextRequest) {
     let currentChat: any = null
     let conversationHistory: any[] = []
     let actualChatId = chatId
-    const selectedModel = model || 'claude-opus-4-6'
+    const selectedModel = model || 'claude-opus-4-5'
 
     if (chatId || createNewChat) {
       const chatResult = await resolveOrCreateChat({
diff --git a/apps/sim/app/api/mcp/copilot/route.ts b/apps/sim/app/api/mcp/copilot/route.ts
index 5fcce8563..643b339f9 100644
--- a/apps/sim/app/api/mcp/copilot/route.ts
+++ b/apps/sim/app/api/mcp/copilot/route.ts
@@ -38,7 +38,7 @@ import {
 
 const logger = createLogger('CopilotMcpAPI')
 const mcpRateLimiter = new RateLimiter()
-const DEFAULT_COPILOT_MODEL = 'claude-opus-4-6'
+const DEFAULT_COPILOT_MODEL = 'claude-opus-4-5'
 
 export const dynamic = 'force-dynamic'
 export const runtime = 'nodejs'
diff --git a/apps/sim/app/api/v1/copilot/chat/route.ts b/apps/sim/app/api/v1/copilot/chat/route.ts
index 9a71ee54b..6a3817385 100644
--- a/apps/sim/app/api/v1/copilot/chat/route.ts
+++ b/apps/sim/app/api/v1/copilot/chat/route.ts
@@ -8,7 +8,7 @@ import { resolveWorkflowIdForUser } from '@/lib/workflows/utils'
 import { authenticateV1Request } from '@/app/api/v1/auth'
 
 const logger = createLogger('CopilotHeadlessAPI')
-const DEFAULT_COPILOT_MODEL = 'claude-opus-4-6'
+const DEFAULT_COPILOT_MODEL = 'claude-opus-4-5'
 
 const RequestSchema = z.object({
   message: z.string().min(1, 'message is required'),