diff --git a/pkg/services/websms_service.go b/pkg/services/websms_service.go
index c1da869..b71413b 100644
--- a/pkg/services/websms_service.go
+++ b/pkg/services/websms_service.go
@@ -92,9 +92,10 @@ func SendWebSms(cfg *models.WebSmsConfig, para, mensaje string) (*WebSmsResponse
 		return nil, fmt.Errorf("websms API status %d: %s", resp.StatusCode, string(respBody))
 	}
 
+	ct := resp.Header.Get("Content-Type")
 	var result WebSmsResponse
 	if err := json.Unmarshal(respBody, &result); err != nil {
-		return nil, fmt.Errorf("websms: unmarshal: %w", err)
+		return nil, fmt.Errorf("websms: respuesta no JSON (Content-Type: %s, cuerpo: %.200s)", ct, string(respBody))
 	}
 
 	return &result, nil