diff --git a/relay/channel/claude/relay-claude.go b/relay/channel/claude/relay-claude.go
index 49768335..5ad9c7af 100644
--- a/relay/channel/claude/relay-claude.go
+++ b/relay/channel/claude/relay-claude.go
@@ -108,6 +108,7 @@ func RequestOpenAI2ClaudeMessage(textRequest dto.GeneralOpenAIRequest) (*ClaudeR
 			Type:         "enabled",
 			BudgetTokens: int(float64(claudeRequest.MaxTokens) * 0.8),
 		}
+		claudeRequest.TopP = 0
 		claudeRequest.Model = strings.TrimSuffix(textRequest.Model, "-thinking")
 	}