diff --git a/Elwig/Helpers/Billing/Billing.cs b/Elwig/Helpers/Billing/Billing.cs
index ad82fee..3f2021c 100644
--- a/Elwig/Helpers/Billing/Billing.cs
+++ b/Elwig/Helpers/Billing/Billing.cs
@@ -43,6 +43,7 @@ namespace Elwig.Helpers.Billing {
         }
 
         public async Task CalculateBins() {
+            var forcedAttr = Context.WineAttributes.Where(a => !a.FillLowerBins).Select(a => a.AttrId).ToArray();
             using var cnx = await AppDbContext.ConnectAsync();
             var memberOblRig = await GetMemberRightsObligations(cnx, Year);
             var inserts = new List<(int, int, int, int, int, int, int)>();
@@ -84,7 +85,7 @@ namespace Elwig.Helpers.Billing {
 
                 int w = weight;
                 int[] b = new int[4];
-                foreach (var p in Utils.Permutate(attributes)) {
+                foreach (var p in Utils.Permutate(attributes, attributes.Intersect(forcedAttr))) {
                     var c = p.Count();
                     var key = sortid + string.Join("", p);
                     if (rights.ContainsKey(key)) {
diff --git a/Elwig/Helpers/Utils.cs b/Elwig/Helpers/Utils.cs
index a2470c3..a5dcd06 100644
--- a/Elwig/Helpers/Utils.cs
+++ b/Elwig/Helpers/Utils.cs
@@ -327,13 +327,14 @@ namespace Elwig.Helpers {
             }
         }
 
-        public static IEnumerable<IEnumerable<T>> Permutate<T>(IEnumerable<T> input) {
-            List<IEnumerable<T>> output = new();
+        public static IEnumerable<IEnumerable<T>> Permutate<T>(IEnumerable<T> input, IEnumerable<T>? forced = null) {
+            HashSet<IEnumerable<T>> output = new();
             for (int i = 0; i < Math.Pow(2, input.Count()); i++) {
                 List<T> t = new();
                 for (int j = 0; j < 30; j++) {
-                    if ((i & (1 << j)) != 0) {
-                        t.Add(input.ElementAt(j));
+                    var e = input.ElementAtOrDefault(j);
+                    if (e != null && ((forced?.Contains(e) ?? false) || (i & (1 << j)) != 0)) {
+                        t.Add(e);
                     }
                 }
                 output.Add(t);