diff --git a/R/rescale_weights.R b/R/rescale_weights.R
index 0c8269baf..340cdf2b4 100644
--- a/R/rescale_weights.R
+++ b/R/rescale_weights.R
@@ -23,9 +23,11 @@
 #' combination from each group level of the variables in `by`.
 #' @param method `"carle"` or `"kish"`.
 #'
-#' @return `data`, including the new weighting variables: `pweights_a`
-#' and `pweights_b`, which represent the rescaled design weights to use
-#' in multilevel models (use these variables for the `weights` argument).
+#' @return `data`, including the new weighting variable(s). For
+#' `method = "carle"`, new columns `pweights_a` and `pweights_b` are returned,
+#' and for `method = "klish"`, the returned data contains a column `pweights`.
+#' These represent the rescaled design weights to use in multilevel models (use
+#' these variables for the `weights` argument).
 #'
 #' @details
 #' - `method = "carle"`
@@ -110,6 +112,11 @@ rescale_weights <- function(data,
     by <- all.vars(by)
   }
 
+  # check for existing variable names
+  if (any(c("pweights_a", "pweights_b", "pweights") %in% colnames(data))) {
+    insight::format_warning("The variable name for the rescaled weights already exists in the data. Existing columns will be overwritten.")
+  }
+
   # check if weight has missings. we need to remove them first,
   # and add back weights to correct cases later
 
diff --git a/man/rescale_weights.Rd b/man/rescale_weights.Rd
index 7b6be3984..25d5a8958 100644
--- a/man/rescale_weights.Rd
+++ b/man/rescale_weights.Rd
@@ -31,9 +31,11 @@ combination from each group level of the variables in \code{by}.}
 \item{method}{\code{"carle"} or \code{"kish"}.}
 }
 \value{
-\code{data}, including the new weighting variables: \code{pweights_a}
-and \code{pweights_b}, which represent the rescaled design weights to use
-in multilevel models (use these variables for the \code{weights} argument).
+\code{data}, including the new weighting variable(s). For
+\code{method = "carle"}, new columns \code{pweights_a} and \code{pweights_b} are returned,
+and for \code{method = "klish"}, the returned data contains a column \code{pweights}.
+These represent the rescaled design weights to use in multilevel models (use
+these variables for the \code{weights} argument).
 }
 \description{
 Most functions to fit multilevel and mixed effects models only