diff --git a/R/teal_data_module-within.R b/R/teal_data_module-within.R
index e81bfa1058..0d478f768c 100644
--- a/R/teal_data_module-within.R
+++ b/R/teal_data_module-within.R
@@ -15,9 +15,9 @@
 #' @examples
 #' within(tdm, dataset1 <- subset(dataset1, Species == "virginica"))
 #'
-#' # in an app, use input-derived value in the expression
-#' within(tdm, dataset1 <- subset(dataset1, Species == species), species = input$species)
-#'
+#' # use additional parameter for expression value substitution.
+#' valid_species = "versicolor"
+#' within(tdm, dataset1 <- subset(dataset1, Species %in% species), species = valid_species)
 #' @include teal_data_module.R
 #' @name within
 #' @rdname teal_data_module
diff --git a/man/teal_data_module.Rd b/man/teal_data_module.Rd
index 5c404d64ae..83878890cf 100644
--- a/man/teal_data_module.Rd
+++ b/man/teal_data_module.Rd
@@ -93,9 +93,9 @@ eval_code(tdm, "dataset1 <- subset(dataset1, Species == 'virginica')")
 
 within(tdm, dataset1 <- subset(dataset1, Species == "virginica"))
 
-# in an app, use input-derived value in the expression
-within(tdm, dataset1 <- subset(dataset1, Species == species), species = input$species)
-
+# use additional parameter for expression value substitution.
+valid_species = "versicolor"
+within(tdm, dataset1 <- subset(dataset1, Species \%in\% species), species = valid_species)
 }
 \seealso{
 \code{\linkS4class{teal_data}}, \code{\link[teal.code:qenv]{teal.code::qenv()}}