diff --git a/src/containers/table.zig b/src/containers/table.zig
index e874f3e..16162a7 100644
--- a/src/containers/table.zig
+++ b/src/containers/table.zig
@@ -94,7 +94,8 @@ pub fn Table(comptime K: type, comptime V: type) type {
             }
 
             if (self.free_list.popOrNull()) |index| {
-                const gen = self.gens.items[index];
+                // gen is bumped on remove *and* re-add. This way, 'active' slots are even and 'inactive' slots are odd.
+                self.gens.items[index] = self.gens.items[index] +% 1;
                 self.keys.items[index] = key;
                 self.values.items[index] = val;
                 try self.lookup.putNoClobber(key, index);
@@ -102,7 +103,7 @@ pub fn Table(comptime K: type, comptime V: type) type {
                 return AddResult{
                     .id = .{
                         .index = index,
-                        .gen = gen,
+                        .gen = self.gens.items[index],
                     },
                     .added = true,
                 };
@@ -226,9 +227,10 @@ test "table across generation" {
 
     // remove first item, then add a new one, then try to access first item!
     _ = try table.remove(table.find(48) orelse unreachable);
+    try std.testing.expectEqual(@as(u8, 1), table.gens.items[0]);
 
     const second_result = try table.add(99, .{ .a = 2, .b = 3 });
-    try std.testing.expectEqual(@as(u8, 1), second_result.id.gen);
+    try std.testing.expectEqual(@as(u8, 2), second_result.id.gen);
 
     try std.testing.expect(!table.exists(first_result.id));
     try std.testing.expectEqual(@as(?*TestVal, null), table.get(first_result.id));
@@ -248,12 +250,12 @@ pub fn RefTable(comptime K: type, comptime V: type) type {
         /// Underlying table.
         table: InternalTable,
         /// Reference counts of the values.
-        ref_counts: std.ArrayList(usize),
+        ref_counts: std.ArrayList(u16),
 
         pub fn init(allocator: std.mem.Allocator) Self {
             return Self{
                 .table = Table(K, V).init(allocator),
-                .ref_counts = std.ArrayList(usize).init(allocator),
+                .ref_counts = std.ArrayList(u16).init(allocator),
             };
         }
 
@@ -411,7 +413,7 @@ test "ref counting" {
     first_result = try table.add(12, .{ .a = 6, .b = 5 });
     try std.testing.expect(first_result.added);
     try std.testing.expectEqual(@as(u24, 0), first_result.id.index);
-    try std.testing.expectEqual(@as(u8, 1), first_result.id.gen);
+    try std.testing.expectEqual(@as(u8, 2), first_result.id.gen);
     const second_result = try table.add(12, .{ .a = 1, .b = 2 });
     try std.testing.expect(!second_result.added);