diff --git a/lib/gear/plotting.py b/lib/gear/plotting.py
index 31398a43..fc5ee254 100644
--- a/lib/gear/plotting.py
+++ b/lib/gear/plotting.py
@@ -472,20 +472,16 @@ def generate_plot(df, x=None, y=None, z=None, facet_row=None, facet_col=None,
         facet_col_groups = []
 
         if facet_row:
-            facet_row_groups = category_orders[facet_row] if facet_row in category_orders else df[facet_row].unique()
+            facet_row_groups = category_orders[facet_row] if facet_row in category_orders else df[facet_row].unique().tolist()
 
         if facet_col:
-            facet_col_groups = category_orders[facet_col] if facet_col in category_orders else df[facet_col].unique()
+            facet_col_groups = category_orders[facet_col] if facet_col in category_orders else df[facet_col].unique().tolist()
 
         facet_row_indexes = {group: idx for idx, group in enumerate(facet_row_groups, start=1)}
         num_rows = len(facet_row_groups) if facet_row else 1
         facet_col_indexes = {group: idx for idx, group in enumerate(facet_col_groups, start=1)}
         num_cols = len(facet_col_groups) if facet_col else 1
 
-        # Ensure facet_row_groups and facet_col_groups elements are cast as strings
-        facet_row_groups = [str(group) for group in facet_row_groups]
-        facet_col_groups = [str(group) for group in facet_col_groups]
-
         # Make faceted plot
         fig = make_subplots(rows=num_rows
                 , cols=num_cols