diff --git a/R/utils.R b/R/utils.R
index e2a5b3e81..b06ac1181 100644
--- a/R/utils.R
+++ b/R/utils.R
@@ -113,7 +113,7 @@
   # insert row
   if (index == 1) {
     rbind(row, data)
-  } else if (index == nrow(data)) {
+  } else if (index == (nrow(data) + 1)) {
     rbind(data, row)
   } else {
     rbind(data[1:(index - 1), ], row, data[index:nrow(data), ])
@@ -121,6 +121,17 @@
 }
 
 
+.insert_element_at <- function(data, element, index) {
+  if (index == 1) {
+    c(element, data)
+  } else if (index == length(data)) {
+    c(data, element)
+  } else {
+    c(data[1:(index - 1)], element, data[index:length(data)])
+  }
+}
+
+
 .find_factor_levels <- function(data) {
   out <- lapply(colnames(data), function(i) {
     v <- data[[i]]
diff --git a/R/utils_format.R b/R/utils_format.R
index be26faef8..494ccad6e 100644
--- a/R/utils_format.R
+++ b/R/utils_format.R
@@ -347,12 +347,31 @@
     params
   }
 
+  pretty_names <- attributes(params)$pretty_names
   out <- params
-  for (f in factors) {
-    min(which(f %in% out$Parameter))
+
+  for (fn in names(factors)) {
+    f <- factors[[fn]]
+    found <- which(names(pretty_names) %in% f)
+    if (length(found)) {
+      reference_level <- f[!f %in% names(pretty_names)]
+      pretty_level <- paste0(fn, " [", sub(fn, "", reference_level, fixed = TRUE), " (ref.)]")
+      pretty_names <- .insert_element_at(
+        pretty_names,
+        stats::setNames(pretty_level, reference_level),
+        min(found)
+      )
+      out <- .insert_row_at(
+        out,
+        data.frame(Parameter = reference_level, Coefficient = 0, stringsAsFactors = FALSE),
+        min(found)
+      )
+    }
+    attr(out, "pretty_names") <- pretty_names
+    attr(out, "pretty_labels") <- pretty_names
   }
 
-  params
+  out
 }