diff --git a/internal/misc/codex_instructions.go b/internal/misc/codex_instructions.go
index d50e8cef..b8370480 100644
--- a/internal/misc/codex_instructions.go
+++ b/internal/misc/codex_instructions.go
@@ -36,7 +36,7 @@ var opencodeCodexInstructions string
 
 const (
 	codexUserAgentKey  = "__cpa_user_agent"
-	userAgentOpenAISDK = "ai-sdk/openai/"
+	userAgentOpenAISDK = "opencode/"
 )
 
 func InjectCodexUserAgent(raw []byte, userAgent string) []byte {