diff --git a/R/format_parameters.R b/R/format_parameters.R
index 9e21d599f..ec3f2b0db 100644
--- a/R/format_parameters.R
+++ b/R/format_parameters.R
@@ -507,6 +507,13 @@ format_parameters.parameters_model <- function(model, ...) {
         for (i in names(interactions)) {
           # extract single coefficient names from interaction term
           out <- unlist(strsplit(i, ":", fixed = TRUE))
+          # for on-the-fly conversion of factors, the names of the factors can
+          # can also contain "factor()" or "as.factor()" - we need to remove these
+          if (any(grepl("(as\\.factor|factor|as\\.character)", out))) {
+            out_clean <- gsub("(as\\.factor|factor|as\\.character)\\((.*)\\)(.*)", "\\2", out)
+          } else {
+            out_clean <- out
+          }
           # combine labels
           labs <- c(
             labs,
diff --git a/R/utils_model_parameters.R b/R/utils_model_parameters.R
index 356305752..8466d1da0 100644
--- a/R/utils_model_parameters.R
+++ b/R/utils_model_parameters.R
@@ -215,7 +215,11 @@
   }
 
   # add parameters with value and variable
-  attr(params, "pretty_labels") <- .format_value_labels(params, model)
+  if (isFALSE(dot.arguments$pretty_names)) {
+    attr(params, "pretty_labels") <- params$Parameter
+  } else if (is.null(attr(params, "pretty_labels", exact = TRUE))) {
+    attr(params, "pretty_labels") <- .format_value_labels(params, model)
+  }
 
   row.names(params) <- NULL
   params