1 files changed, 3 insertions, 2 deletions
diff --git a/src/ninep/tree.zig b/src/ninep/tree.zig
index e6c139c1..40543ecf 100644
--- a/src/ninep/tree.zig
+++ b/src/ninep/tree.zig
@@ -1905,10 +1905,11 @@ test "no placement leaves a pane shorter than its tag and two rows; a full colum
     } else return error.NeverRefused;
     try testing.expectEqual(E.NOSPC, refused.errno());
     try testing.expect(std.mem.indexOf(u8, refused.reply.ename, "no space for a pane in that column") != null);
-    // The refused pane was never there: no serial spent on it.
+    // The refused pane was never there; its serial is not handed out again
+    // (gaps are fine: a serial once said names one pane for good).
     const before = p.next_serial;
     try testing.expectEqual(E.NOSPC, call(p, .{ .tag = 1, .op = .open, .node = new }).errno());
-    try testing.expectEqual(before, p.next_serial);
+    try testing.expectEqual(before + 1, p.next_serial);
     p.sync();
     var count: usize = 0;
     for (p.panes) |slot| count += @intFromBool(slot != null);