diff --git a/instat/static/InstatObject/R/Backend_Components/calculations.R b/instat/static/InstatObject/R/Backend_Components/calculations.R
index 2f3191c214..6f1b349524 100644
--- a/instat/static/InstatObject/R/Backend_Components/calculations.R
+++ b/instat/static/InstatObject/R/Backend_Components/calculations.R
@@ -494,7 +494,7 @@ DataBook$set("public", "apply_instat_calculation", function(calc, curr_data_list
       # if it is a ordered factor...
       if (any(stringr::str_detect("ordered", col_data_type))){
         # put in here the ones that DO work for ordered factor
-        if (any(grepl("summary_count_non_missing|summary_count_missing|summary_count|summary_min|summary_max|summary_range|summary_median|summary_quantile|p10|p20|p25|p30|p33|p40|p60|p67|p70|p75|p80|p90", formula_fn_exp))){
+        if (any(grepl("summary_count_non_missing|summary_count_missing|summary_n_distinct|summary_count|summary_min|summary_max|summary_range|summary_median|summary_quantile|p10|p20|p25|p30|p33|p40|p60|p67|p70|p75|p80|p90", formula_fn_exp))){
           curr_data_list[[c_data_label]] <- curr_data_list[[c_data_label]] %>%
             dplyr::summarise(!!calc$result_name := !!rlang::parse_expr(calc$function_exp))
         } else {
@@ -505,7 +505,7 @@ DataBook$set("public", "apply_instat_calculation", function(calc, curr_data_list
         # if it is a factor or character, do not work for anything except...
       } else if (any(stringr::str_detect("factor | character", col_data_type))){
         # put in here the ones that DO work for factor or character
-        if (any(grepl("summary_count_non_missing|summary_count_missing|summary_count", formula_fn_exp))){
+        if (any(grepl("summary_count_non_missing|summary_count_missing|summary_n_distinct|summary_count", formula_fn_exp))){
           curr_data_list[[c_data_label]] <- curr_data_list[[c_data_label]] %>%
             dplyr::summarise(!!calc$result_name := !!rlang::parse_expr(calc$function_exp)) 
         } else {
@@ -846,4 +846,4 @@ find_df_from_calc_from <- function(x, column) {
     if(column %in% x[[i]]) return(names(x)[i])
   }
   return("")
-}
\ No newline at end of file
+}
diff --git a/instat/static/InstatObject/R/Backend_Components/summary_functions.R b/instat/static/InstatObject/R/Backend_Components/summary_functions.R
index 397a72b261..4371ef7556 100644
--- a/instat/static/InstatObject/R/Backend_Components/summary_functions.R
+++ b/instat/static/InstatObject/R/Backend_Components/summary_functions.R
@@ -1113,7 +1113,7 @@ summary_nth <- function(x, nth_value, order_by = NULL, ...) {
 
 # n_distinct function
 summary_n_distinct<- function(x, na.rm = FALSE, ...) {
-  return(dplyr::n_distinct(x = x, na.rm = na.rm))
+  return(dplyr::n_distinct(x, na.rm = na.rm))
 }
 
 # sample function