diff --git a/lib/DB.zig b/lib/DB.zig
index 5b05e58..1b9ebff 100644
--- a/lib/DB.zig
+++ b/lib/DB.zig
@@ -119,6 +119,8 @@ pub fn fromCorpus(
         .nblocks_users = nblocks(u64, users.blob),
         .nblocks_groupmembers = nblocks(u64, groupmembers.blob),
         .nblocks_additional_gids = nblocks(u64, additional_gids.blob),
+        .getgr_max = 0,
+        .getpw_max = 0,
     };
 
     return DB{
@@ -628,6 +630,7 @@ test "high-level API" {
 
     var arena = ArenaAllocator.init(allocator);
     defer arena.deinit();
+    // TODO: should accept a buffer instead of an allocator instead.
     const all = try db.getgrnam(arena.allocator(), "all");
     try testing.expect(all != null);
     try testing.expectEqual(all.?.gid, 9999);
diff --git a/lib/header.zig b/lib/header.zig
index bcd406a..516cf6d 100644
--- a/lib/header.zig
+++ b/lib/header.zig
@@ -44,6 +44,9 @@ pub const Header = packed struct {
     nblocks_users: u64,
     nblocks_groupmembers: u64,
     nblocks_additional_gids: u64,
+    getgr_max: u64,
+    getpw_max: u64,
+    padding: [48]u8 = [1]u8{0} ** 48,
 
     pub fn fromBytes(blob: *const [@sizeOf(Header)]u8) Invalid!*const Header {
         const self = mem.bytesAsValue(Header, blob);
@@ -67,8 +70,8 @@ test "Section length is a power of two" {
     try testing.expect(std.math.isPowerOfTwo(section_length));
 }
 
-test "Header fits into a section" {
-    try testing.expect(@sizeOf(Header) <= section_length);
+test "Header fits into two section" {
+    try testing.expect(@sizeOf(Header) == 2 * section_length);
 }
 
 test "bit header size is equal to @sizeOf(Header)" {
@@ -89,6 +92,8 @@ test "header pack and unpack" {
         .nblocks_users = 0,
         .nblocks_groupmembers = 0,
         .nblocks_additional_gids = 1,
+        .getgr_max = 0,
+        .getpw_max = 0,
     };
 
     const bytes = mem.asBytes(&header1);