diff --git a/NAMESPACE b/NAMESPACE
index 969ce905f..c41ef7009 100644
--- a/NAMESPACE
+++ b/NAMESPACE
@@ -1,5 +1,6 @@
 # Generated by roxygen2: do not edit by hand
 
+S3method(as_forecast,default)
 S3method(print,scoringutils_check)
 S3method(quantile_to_interval,data.frame)
 S3method(quantile_to_interval,numeric)
diff --git a/R/validate.R b/R/validate.R
index f8b20ab98..65da31eba 100644
--- a/R/validate.R
+++ b/R/validate.R
@@ -19,7 +19,13 @@
 #' @examples
 #' as_forecast(example_binary)
 #' as_forecast(example_quantile)
-as_forecast <- function(data) {
+as_forecast <- function(data, ...) {
+  UseMethod("as_forecast")
+}
+
+#' @rdname as_forecast
+#' @export
+as_forecast.default <- function(data, ...) {
   assert(check_data_columns(data))
 
   # find forecast type
diff --git a/man/as_forecast.Rd b/man/as_forecast.Rd
index 3c8f8de6e..11e6091ce 100644
--- a/man/as_forecast.Rd
+++ b/man/as_forecast.Rd
@@ -2,12 +2,17 @@
 % Please edit documentation in R/validate.R
 \name{as_forecast}
 \alias{as_forecast}
+\alias{as_forecast.default}
 \title{Create a \code{forecast} Object}
 \usage{
-as_forecast(data)
+as_forecast(data, ...)
+
+\method{as_forecast}{default}(data, ...)
 }
 \arguments{
 \item{data}{A data.frame or data.table with predicted and observed values.}
+
+\item{...}{additional arguments}
 }
 \value{
 Depending on the forecast type, an object of class