diff --git a/src/terminal/snapshot/history.zig b/src/terminal/snapshot/history.zig
index b49c05081..dc5fcb65d 100644
--- a/src/terminal/snapshot/history.zig
+++ b/src/terminal/snapshot/history.zig
@@ -7,15 +7,13 @@
 //! to oldest.
 //!
 //! Every encoded SCREEN has one corresponding HISTORY record. A screen with no
-//! history uses zero for all three count fields and has no following PAGE
-//! records.
+//! older pages uses a zero page count and has no following PAGE records.
 //!
 //! The first SCREEN page may begin above the active area. Those incidental
-//! history rows are counted by `screen_overlap_rows`; they are not repeated
-//! after HISTORY. `total_rows` is the canonical number of logical rows before
-//! the active area, including both the SCREEN overlap and the rows in the
-//! following PAGE records. Decoders derive native row totals from the restored
-//! pages and may ignore inconsistent row metadata.
+//! history rows are already present at READY and are not repeated after
+//! HISTORY. The corresponding SCREEN header declares the complete logical
+//! history extent, including both that resident overlap and the following PAGE
+//! records.
 //!
 //! All integers are unsigned and little-endian.
 //!
@@ -53,17 +51,10 @@
 //!  2 +--------------------------------+
 //!    | Following page count (u32)     |
 //!  6 +--------------------------------+
-//!    | Total logical history rows     |
-//!    | u64                            |
-//! 14 +--------------------------------+
-//!    | SCREEN overlap rows (u16)      |
-//! 16 +--------------------------------+
 //! ```
 //!
-//! A canonical encoder sets `total_rows` to the sum of `screen_overlap_rows`
-//! and the logical row counts of all following PAGE records. A decoder uses
-//! `page_count`, rather than another record tag, to find the end of the page
-//! sequence.
+//! A decoder uses `page_count`, rather than another record tag, to find the end
+//! of the page sequence.
 
 const std = @import("std");
 const Allocator = std.mem.Allocator;
@@ -85,7 +76,7 @@ pub const Header = struct {
     comptime {
         // This size is part of the wire format. If it changes, the snapshot
         // version must also change.
-        std.debug.assert(len == 16);
+        std.debug.assert(len == 6);
     }
 
     /// Identifies the previously encoded screen that owns this history.
@@ -94,12 +85,6 @@ pub const Header = struct {
     /// Number of complete PAGE records immediately following this record.
     page_count: u32,
 
-    /// Canonical number of logical rows before the active area.
-    total_rows: u64,
-
-    /// History rows already included at the start of the first SCREEN page.
-    screen_overlap_rows: u16,
-
     /// Encode the fixed HISTORY payload.
     pub fn encode(
         self: Header,
@@ -107,8 +92,6 @@ pub const Header = struct {
     ) std.Io.Writer.Error!void {
         try io.writeInt(writer, u16, @intCast(@intFromEnum(self.key)));
         try io.writeInt(writer, u32, self.page_count);
-        try io.writeInt(writer, u64, self.total_rows);
-        try io.writeInt(writer, u16, self.screen_overlap_rows);
     }
 
     pub const DecodeError = std.Io.Reader.Error || error{InvalidKey};
@@ -126,8 +109,6 @@ pub const Header = struct {
         return .{
             .key = key,
             .page_count = try io.readInt(reader, u32),
-            .total_rows = try io.readInt(reader, u64),
-            .screen_overlap_rows = try io.readInt(reader, u16),
         };
     }
 
@@ -138,8 +119,6 @@ pub const Header = struct {
             const value: Header = .{
                 .key = .primary,
                 .page_count = 0,
-                .total_rows = 0,
-                .screen_overlap_rows = 0,
             };
             value.encode(&writer) catch unreachable;
             return writer.end;
@@ -154,9 +133,6 @@ pub const EncodeError = Allocator.Error ||
     error{
         /// The complete historical prefix has more pages than the header fits.
         PageCountOverflow,
-
-        /// The complete historical prefix has more rows than the header fits.
-        RowCountOverflow,
     };
 
 /// Encode one screen's HISTORY and its complete historical pages.
@@ -172,21 +148,14 @@ pub fn encode(
     // SCREEN begins at the page containing the active area's first row. Its
     // leading rows are already resident; every previous complete page belongs
     // to this HISTORY sequence.
-    const active_top = terminal_screen.pages.getTopLeft(.active);
-    const page_count: usize, const total_rows: u64 = count: {
+    const first = terminal_screen.pages.getTopLeft(.active).node.prev;
+    const page_count: usize = count: {
         var page_count: usize = 0;
-        var total_rows: u64 = active_top.y;
-        var node = active_top.node.prev;
+        var node = first;
         while (node) |current| : (node = current.prev) {
             page_count += 1;
-            total_rows = std.math.add(
-                u64,
-                total_rows,
-                current.rows(),
-            ) catch return error.RowCountOverflow;
         }
-
-        break :count .{ page_count, total_rows };
+        break :count page_count;
     };
 
     const header: Header = .{
@@ -195,12 +164,9 @@ pub fn encode(
             u32,
             page_count,
         ) orelse return error.PageCountOverflow,
-        .total_rows = total_rows,
-        .screen_overlap_rows = active_top.y,
     };
 
-    // HISTORY declares exactly how many PAGE records follow and how their rows
-    // combine with the overlap already carried by SCREEN.
+    // HISTORY declares exactly how many PAGE records follow.
     {
         const payload = destination.begin(.history);
         errdefer destination.cancel();
@@ -211,7 +177,7 @@ pub fn encode(
     // Walk backward so each page can be prepended by the decoder immediately.
     // PreservedPage borrows resident pages and clones compressed pages without
     // changing the source node's representation.
-    var node = active_top.node.prev;
+    var node = first;
     while (node) |current| : (node = current.prev) {
         var preserved = try current.pagePreservingState(terminal_screen.alloc);
         defer preserved.deinit();
@@ -277,9 +243,7 @@ pub const Decoder = struct {
             return error.ExistingHistory;
         }
 
-        // Row metadata is redundant with the restored SCREEN and PAGE
-        // topology. Consume the declared PAGE records, but derive all native
-        // row totals from their actual dimensions.
+        // Native row totals remain derived from the actual PAGE dimensions.
         for (0..self.header.page_count) |_| {
             // PAGE exposes its exact capacity before decoding the payload,
             // allowing the destination PageList to allocate the final backing
@@ -341,8 +305,6 @@ test "HISTORY header golden encoding and decoding" {
     const expected: Header = .{
         .key = .alternate,
         .page_count = 0x01020304,
-        .total_rows = 0x0102030405060708,
-        .screen_overlap_rows = 0x090a,
     };
     var encoded: [Header.len]u8 = undefined;
     var writer: std.Io.Writer = .fixed(&encoded);
@@ -456,16 +418,6 @@ test "HISTORY encodes newest first and restores complete history" {
     try history_record.finish();
     try std.testing.expectEqual(TerminalScreenKey.primary, header.key);
     try std.testing.expectEqual(@as(u32, 2), header.page_count);
-    try std.testing.expectEqual(
-        @as(u16, active_top.y),
-        header.screen_overlap_rows,
-    );
-    try std.testing.expectEqual(
-        @as(u64, active_top.y) +
-            oldest_history.rows() +
-            newest_history.rows(),
-        header.total_rows,
-    );
 
     var decoded_newest = try page.decode(
         &history_source,
@@ -504,6 +456,10 @@ test "HISTORY encodes newest first and restores complete history" {
         TerminalScreenKey.primary,
         decoded_screen.key,
     );
+    try std.testing.expectEqual(
+        @as(u64, @intCast(source_screen.pages.total_rows - screen_rows)),
+        decoded_screen.history_rows,
+    );
     const restored = &decoded_screen.screen;
     try std.testing.expect(!restored.semantic_prompt.seen);
     try decode(
@@ -660,8 +616,6 @@ test "HISTORY encodes and restores an empty sequence" {
     const header = try Header.decode(history_record.payloadReader());
     try history_record.finish();
     try std.testing.expectEqual(@as(u32, 0), header.page_count);
-    try std.testing.expectEqual(@as(u64, 0), header.total_rows);
-    try std.testing.expectEqual(@as(u16, 0), header.screen_overlap_rows);
     try std.testing.expectError(error.EndOfStream, inspect_source.takeByte());
 
     var decode_source: std.Io.Reader = .fixed(destination.written());
@@ -679,7 +633,7 @@ test "HISTORY encodes and restores an empty sequence" {
     try std.testing.expectError(error.EndOfStream, decode_source.takeByte());
 }
 
-test "HISTORY accepts row metadata mismatches and rejects structural ones" {
+test "HISTORY rejects invalid routing and incomplete sequences" {
     var terminal_screen = try TerminalScreen.init(
         std.testing.io,
         std.testing.allocator,
@@ -691,49 +645,6 @@ test "HISTORY accepts row metadata mismatches and rejects structural ones" {
     );
     defer terminal_screen.deinit();
 
-    // Row counts are redundant metadata. Even internally inconsistent values
-    // do not prevent restoring the topology declared by page_count.
-    const accepted = [_]Header{
-        .{
-            .key = .primary,
-            .page_count = 0,
-            .total_rows = 0,
-            .screen_overlap_rows = 1,
-        },
-        .{
-            .key = .primary,
-            .page_count = 0,
-            .total_rows = std.math.maxInt(u64),
-            .screen_overlap_rows = std.math.maxInt(u16),
-        },
-    };
-    for (accepted) |header| {
-        var destination: std.Io.Writer.Allocating = .init(
-            std.testing.allocator,
-        );
-        defer destination.deinit();
-        var stream: record.Writer = .init(
-            std.testing.allocator,
-            &destination.writer,
-        );
-        defer stream.deinit();
-        const payload = stream.begin(.history);
-        errdefer stream.cancel();
-        try header.encode(payload);
-        try stream.finish();
-
-        var source: std.Io.Reader = .fixed(destination.written());
-        try decode(
-            &source,
-            std.testing.allocator,
-            .primary,
-            &terminal_screen,
-        );
-        try std.testing.expectError(error.EndOfStream, source.takeByte());
-        terminal_screen.pages.assertIntegrity();
-        terminal_screen.assertIntegrity();
-    }
-
     // Routing and sequence length still determine which native screen is
     // mutated and where the following record begins, so they remain strict.
     const Case = struct {
@@ -745,8 +656,6 @@ test "HISTORY accepts row metadata mismatches and rejects structural ones" {
             .header = .{
                 .key = .alternate,
                 .page_count = 0,
-                .total_rows = 0,
-                .screen_overlap_rows = 0,
             },
             .expected = error.UnexpectedScreenKey,
         },
@@ -754,8 +663,6 @@ test "HISTORY accepts row metadata mismatches and rejects structural ones" {
             .header = .{
                 .key = .primary,
                 .page_count = 1,
-                .total_rows = 1,
-                .screen_overlap_rows = 0,
             },
             .expected = error.EndOfStream,
         },
diff --git a/src/terminal/snapshot/main.zig b/src/terminal/snapshot/main.zig
index d1d092d59..6eb580f21 100644
--- a/src/terminal/snapshot/main.zig
+++ b/src/terminal/snapshot/main.zig
@@ -74,7 +74,9 @@
 //! READY and FINISH contain BLAKE3-256 digests of all preceding snapshot bytes.
 //! READY therefore validates the renderable active-state prefix. FINISH covers
 //! READY and all history as well, validating the complete snapshot and its
-//! record ordering.
+//! record ordering. Each SCREEN declares its complete logical history extent,
+//! allowing a client to size its scrollbar at READY even though older PAGE
+//! records arrive afterward.
 //!
 //! ## Encoding
 //!
diff --git a/src/terminal/snapshot/screen.zig b/src/terminal/snapshot/screen.zig
index 2fc3d0d8b..875d2bb0e 100644
--- a/src/terminal/snapshot/screen.zig
+++ b/src/terminal/snapshot/screen.zig
@@ -9,13 +9,14 @@
 //!
 //! The final screen-height rows are the active area. When its boundary falls
 //! inside the first encoded page, that page also contains an incidental history
-//! prefix. A client may expose or ignore those resident rows, but must not
-//! require them or infer the complete history extent from them.
+//! prefix. `history_rows` declares the complete logical history extent so a
+//! client can size its scrollbar at READY without waiting for HISTORY. A client
+//! may expose or ignore the resident overlap carried by SCREEN. The extent is
+//! advisory; native row totals remain derived from decoded PAGE records.
 //!
 //! Screen dimensions are terminal-wide state and are not repeated here. Page
-//! capacities, native page IDs and pointers, authoritative history extent and
-//! availability, scrollbar state, selection, viewport, dirty state, and derived
-//! semantic-prompt state are also omitted.
+//! capacities, native page IDs and pointers, history availability, selection,
+//! viewport, dirty state, and derived semantic-prompt state are also omitted.
 //!
 //! All integers are unsigned and little-endian.
 //!
@@ -37,10 +38,9 @@
 //!  n = page_count
 //! ```
 //!
-//! The HISTORY record for this screen provides the authoritative history
-//! manifest. It counts any incidental prefix above as the SCREEN overlap, then
-//! sends the older complete pages after the terminal becomes ready. The prefix
-//! is not sent again.
+//! The HISTORY record for this screen declares and sends the older complete
+//! pages after the terminal becomes ready. The incidental prefix is already
+//! present in SCREEN and is not sent again.
 //!
 //! The SCREEN payload begins with a fixed header. When the header says there is
 //! no saved cursor, the payload is:
@@ -48,7 +48,7 @@
 //! ```text
 //!   0 +----------------------+
 //!     | Header               |
-//!  45 +----------------------+
+//!  53 +----------------------+
 //!     | Cursor hyperlink     |
 //!     | variable             |
 //! end +----------------------+
@@ -59,9 +59,9 @@
 //! ```text
 //!   0 +----------------------+
 //!     | Header               |
-//!  45 +----------------------+
+//!  53 +----------------------+
 //!     | Saved cursor         |
-//!  68 +----------------------+
+//!  76 +----------------------+
 //!     | Cursor hyperlink     |
 //!     | variable             |
 //! end +----------------------+
@@ -79,33 +79,35 @@
 //!   2 +----------------------------------+
 //!     | Page count (u16)                 |
 //!   4 +----------------------------------+
+//!     | Logical history rows (u64)       |
+//!  12 +----------------------------------+
 //!     | Cursor x (u16)                   |
-//!   6 +----------------------------------+
+//!  14 +----------------------------------+
 //!     | Cursor y (u16)                   |
-//!   8 +----------------------------------+
+//!  16 +----------------------------------+
 //!     | Cursor visual style (u8)         |
-//!   9 +----------------------------------+
+//!  17 +----------------------------------+
 //!     | Cursor flags (u8)                |
-//!  10 +----------------------------------+
+//!  18 +----------------------------------+
 //!     | Concrete cursor pen (Style)      |
-//!  26 +----------------------------------+
-//!     | Hyperlink implicit counter (u32) |
-//!  30 +----------------------------------+
-//!     | Current charset (CharsetState)   |
-//!  32 +----------------------------------+
-//!     | Protected mode (u8)              |
-//!  33 +----------------------------------+
-//!     | Kitty keyboard stack index (u8)  |
 //!  34 +----------------------------------+
+//!     | Hyperlink implicit counter (u32) |
+//!  38 +----------------------------------+
+//!     | Current charset (CharsetState)   |
+//!  40 +----------------------------------+
+//!     | Protected mode (u8)              |
+//!  41 +----------------------------------+
+//!     | Kitty keyboard stack index (u8)  |
+//!  42 +----------------------------------+
 //!     | Kitty keyboard stack flags       |
 //!     | 8 * u8                           |
-//!  42 +----------------------------------+
+//!  50 +----------------------------------+
 //!     | Semantic-click kind (u8)         |
-//!  43 +----------------------------------+
+//!  51 +----------------------------------+
 //!     | Semantic-click value (u8)        |
-//!  44 +----------------------------------+
+//!  52 +----------------------------------+
 //!     | Saved-cursor-present (u8)        |
-//!  45 +----------------------------------+
+//!  53 +----------------------------------+
 //! ```
 //!
 //! The concrete cursor pen uses the fixed style encoding from `style.zig`.
@@ -298,6 +300,8 @@ pub const DecodeError = PayloadDecodeError ||
 /// One decoded SCREEN sequence and the native screen identified by its header.
 pub const Decoded = struct {
     key: TerminalScreenKey,
+    /// Expected history extent at READY, including resident SCREEN overlap.
+    history_rows: u64,
     screen: TerminalScreen,
 
     /// Release the decoded native screen before ownership is transferred.
@@ -507,7 +511,11 @@ pub fn decode(
     // before transferring ownership to the caller.
     result.pages.assertIntegrity();
     result.assertIntegrity();
-    return .{ .key = key, .screen = result };
+    return .{
+        .key = key,
+        .history_rows = header.history_rows,
+        .screen = result,
+    };
 }
 
 /// Errors possible while decoding fixed SCREEN payload fields.
@@ -868,12 +876,15 @@ pub const Header = struct {
     pub const len = computeLen();
 
     comptime {
-        std.debug.assert(len == 45);
+        std.debug.assert(len == 53);
     }
 
     key: TerminalScreenKey,
     /// Complete pages in the minimal suffix covering the active area.
     page_count: u16,
+    /// Advisory logical rows before the active area, including resident
+    /// SCREEN overlap.
+    history_rows: u64,
     cursor_x: u16,
     cursor_y: u16,
     cursor_style: TerminalScreen.CursorStyle,
@@ -895,6 +906,9 @@ pub const Header = struct {
         return .{
             .key = key,
             .page_count = page_count,
+            .history_rows = @intCast(
+                screen.pages.total_rows - screen.pages.rows,
+            ),
             .cursor_x = screen.cursor.x,
             .cursor_y = screen.cursor.y,
             .cursor_style = screen.cursor.cursor_style,
@@ -932,9 +946,10 @@ pub const Header = struct {
             }
         }
 
-        // Screen identity and cursor position.
+        // Screen identity, expected history extent, and cursor position.
         try io.writeInt(writer, u16, @intCast(@intFromEnum(self.key)));
         try io.writeInt(writer, u16, self.page_count);
+        try io.writeInt(writer, u64, self.history_rows);
         try io.writeInt(writer, u16, self.cursor_x);
         try io.writeInt(writer, u16, self.cursor_y);
 
@@ -975,12 +990,13 @@ pub const Header = struct {
     /// The screen key remains structural because it routes the following PAGE
     /// sequence. Unknown semantic fields use native defaults instead.
     pub fn decode(reader: *std.Io.Reader) PayloadDecodeError!Header {
-        // Screen identity and cursor position.
+        // Screen identity, expected history extent, and cursor position.
         const key = enumFromInt(
             TerminalScreenKey,
             try io.readInt(reader, u16),
         ) orelse return error.InvalidKey;
         const page_count = try io.readInt(reader, u16);
+        const history_rows = try io.readInt(reader, u64);
         const cursor_x = try io.readInt(reader, u16);
         const cursor_y = try io.readInt(reader, u16);
 
@@ -1012,6 +1028,7 @@ pub const Header = struct {
         return .{
             .key = key,
             .page_count = page_count,
+            .history_rows = history_rows,
             .cursor_x = cursor_x,
             .cursor_y = cursor_y,
 
@@ -1037,6 +1054,7 @@ pub const Header = struct {
             const value: Header = .{
                 .key = .primary,
                 .page_count = 0,
+                .history_rows = 0,
                 .cursor_x = 0,
                 .cursor_y = 0,
                 .cursor_style = .bar,
@@ -1135,6 +1153,7 @@ fn testHeader() Header {
     return .{
         .key = .alternate,
         .page_count = 0x0203,
+        .history_rows = 0x0102030405060708,
         .cursor_x = 0x0405,
         .cursor_y = 0x0607,
         .cursor_style = .block_hollow,
@@ -1444,16 +1463,16 @@ test "header decoding rejects structural values" {
 test "header decoding normalizes unknown semantic values" {
     var fixture = [_]u8{0} ** Header.len;
 
-    fixture[8] = 4; // Unknown cursor style.
-    fixture[9] = 0xFF; // Known flags, unknown semantic value, reserved bits.
-    fixture[10] = 3; // Unknown cursor foreground color kind.
-    fixture[31] = 0xD0; // Invalid single shift plus a reserved bit.
-    fixture[32] = 3; // Unknown protected mode.
-    fixture[33] = 8; // Out-of-range Kitty keyboard index.
-    @memset(fixture[34..42], 0xFF); // Known flags plus reserved bits.
-    fixture[42] = 3; // Unknown semantic-click kind.
-    fixture[43] = 0xFF;
-    fixture[44] = 2; // Noncanonical true.
+    fixture[16] = 4; // Unknown cursor style.
+    fixture[17] = 0xFF; // Known flags, unknown semantic value, reserved bits.
+    fixture[18] = 3; // Unknown cursor foreground color kind.
+    fixture[39] = 0xD0; // Invalid single shift plus a reserved bit.
+    fixture[40] = 3; // Unknown protected mode.
+    fixture[41] = 8; // Out-of-range Kitty keyboard index.
+    @memset(fixture[42..50], 0xFF); // Known flags plus reserved bits.
+    fixture[50] = 3; // Unknown semantic-click kind.
+    fixture[51] = 0xFF;
+    fixture[52] = 2; // Noncanonical true.
 
     var reader: std.Io.Reader = .fixed(&fixture);
     const decoded = try Header.decode(&reader);
@@ -1504,8 +1523,8 @@ test "header decoding normalizes unknown semantic values" {
     };
     for (invalid_semantic_clicks) |invalid| {
         var semantic_fixture = [_]u8{0} ** Header.len;
-        semantic_fixture[42] = invalid[0];
-        semantic_fixture[43] = invalid[1];
+        semantic_fixture[50] = invalid[0];
+        semantic_fixture[51] = invalid[1];
         var semantic_reader: std.Io.Reader = .fixed(&semantic_fixture);
         const semantic_decoded = try Header.decode(&semantic_reader);
         try std.testing.expectEqual(
@@ -1541,6 +1560,7 @@ test "native SCREEN payload omits absent optional state" {
     const header = try Header.decode(&reader);
     try std.testing.expectEqual(TerminalScreenKey.primary, header.key);
     try std.testing.expectEqual(@as(u16, 1), header.page_count);
+    try std.testing.expectEqual(@as(u64, 0), header.history_rows);
     try std.testing.expect(!header.saved_cursor_present);
     try std.testing.expectEqual(
         null,
@@ -1867,6 +1887,10 @@ test "SCREEN encodes the minimal complete-page active suffix" {
     const header = try Header.decode(payload_reader);
     try std.testing.expectEqual(TerminalScreenKey.primary, header.key);
     try std.testing.expectEqual(@as(u16, 2), header.page_count);
+    try std.testing.expectEqual(
+        @as(u64, @intCast(screen.pages.total_rows - screen.pages.rows)),
+        header.history_rows,
+    );
     try std.testing.expect(!header.saved_cursor_present);
     try std.testing.expectEqual(
         null,
@@ -1904,11 +1928,22 @@ test "SCREEN encodes the minimal complete-page active suffix" {
     );
     defer decoded.deinit();
     try std.testing.expectEqual(TerminalScreenKey.primary, decoded.key);
+    try std.testing.expectEqual(header.history_rows, decoded.history_rows);
     const restored = &decoded.screen;
 
     try std.testing.expectEqual(@as(usize, 2), restored.pages.totalPages());
     const restored_top = restored.pages.getTopLeft(.active);
     try std.testing.expectEqual(@as(u16, 1), restored_top.y);
+    try std.testing.expectEqual(
+        @as(usize, restored_top.y),
+        restored.pages.total_rows - restored.pages.rows,
+    );
+    try std.testing.expect(
+        decoded.history_rows > @as(
+            u64,
+            @intCast(restored.pages.total_rows - restored.pages.rows),
+        ),
+    );
     try std.testing.expectEqual(
         @as(u21, 'B'),
         restored.pages.getTopLeft(.screen).node
diff --git a/src/terminal/snapshot/snapshot.ksy b/src/terminal/snapshot/snapshot.ksy
index b7f8eb1bf..ad8f6c3a0 100644
--- a/src/terminal/snapshot/snapshot.ksy
+++ b/src/terminal/snapshot/snapshot.ksy
@@ -11,7 +11,8 @@ doc: |
   renderable screen sequences, a READY checkpoint, matching history sequences,
   and a FINISH checkpoint. SCREEN pages are oldest-to-newest. HISTORY pages are
   newest-to-oldest. FINISH terminates the snapshot; bytes that follow belong to
-  the containing transport and are outside this schema.
+  the containing transport and are outside this schema. Each SCREEN declares
+  its complete logical history extent before READY.
 
   Record CRC32C values and checkpoint BLAKE3-256 digests are represented here
   but cannot be calculated by portable Kaitai Struct expressions. The adjacent
@@ -568,6 +569,8 @@ types:
         type: u2
         valid:
           min: 1
+      - id: history_rows
+        type: u8
       - id: cursor_x
         type: u2
       - id: cursor_y
@@ -710,10 +713,6 @@ types:
           expr: _.to_i <= 1
       - id: page_count
         type: u4
-      - id: total_rows
-        type: u8
-      - id: screen_overlap_rows
-        type: u2
       - id: trailing_data
         size-eos: true
         valid:
diff --git a/src/terminal/snapshot/testdata/complete-v1.hex b/src/terminal/snapshot/testdata/complete-v1.hex
index 01a72f1ea..7731a9c9d 100644
--- a/src/terminal/snapshot/testdata/complete-v1.hex
+++ b/src/terminal/snapshot/testdata/complete-v1.hex
@@ -72,70 +72,68 @@ ee ee 80 00 00 00 00 00 00 00 00 00 00 00 00 00 # 0x0000037a
 00 63 6f 6d 70 6c 65 74 65 20 73 6e 61 70 73 68 # 0x000003ba
 6f 74 # 0x000003ca
 
-# offset 0x000003cc: screen record, payload 46 bytes
-02 00 2e 00 00 00 dc 02 f1 37 00 00 01 00 00 00 # 0x000003cc
-00 00 01 00 00 00 00 00 00 00 00 00 00 00 00 00 # 0x000003dc
-00 00 00 00 00 00 00 00 00 08 00 00 00 00 00 00 # 0x000003ec
-00 00 00 00 00 00 00 00 # 0x000003fc
+# offset 0x000003cc: screen record, payload 54 bytes
+02 00 36 00 00 00 67 31 0e c6 00 00 01 00 04 00 # 0x000003cc
+00 00 00 00 00 00 00 00 00 00 01 00 00 00 00 00 # 0x000003dc
+00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 # 0x000003ec
+00 08 00 00 00 00 00 00 00 00 00 00 00 00 00 00 # 0x000003fc
 
-# offset 0x00000404: page record, payload 119 bytes
-03 00 77 00 00 00 48 b7 91 cb 02 00 03 00 00 00 # 0x00000404
-00 00 10 00 c0 00 00 04 00 00 00 08 00 00 00 00 # 0x00000414
-00 00 00 00 00 00 00 43 00 00 00 00 00 00 00 00 # 0x00000424
-00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 # 0x00000434
-00 00 00 00 00 00 00 00 44 00 00 00 00 00 00 00 # 0x00000444
-00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 # 0x00000454
-00 00 00 00 00 00 00 00 00 45 00 00 00 00 00 00 # 0x00000464
-00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 # 0x00000474
-00 # 0x00000484
+# offset 0x0000040c: page record, payload 119 bytes
+03 00 77 00 00 00 48 b7 91 cb 02 00 03 00 00 00 # 0x0000040c
+00 00 10 00 c0 00 00 04 00 00 00 08 00 00 00 00 # 0x0000041c
+00 00 00 00 00 00 00 43 00 00 00 00 00 00 00 00 # 0x0000042c
+00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 # 0x0000043c
+00 00 00 00 00 00 00 00 44 00 00 00 00 00 00 00 # 0x0000044c
+00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 # 0x0000045c
+00 00 00 00 00 00 00 00 00 45 00 00 00 00 00 00 # 0x0000046c
+00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 # 0x0000047c
+00 # 0x0000048c
 
-# offset 0x00000485: screen record, payload 46 bytes
-02 00 2e 00 00 00 05 b9 5a 3a 01 00 01 00 01 00 # 0x00000485
-02 00 01 00 00 00 00 00 00 00 00 00 00 00 00 00 # 0x00000495
-00 00 00 00 00 00 00 00 00 08 00 00 00 00 00 00 # 0x000004a5
-00 00 00 00 00 00 00 00 # 0x000004b5
+# offset 0x0000048d: screen record, payload 54 bytes
+02 00 36 00 00 00 ce 1f 9f 08 01 00 01 00 00 00 # 0x0000048d
+00 00 00 00 00 00 01 00 02 00 01 00 00 00 00 00 # 0x0000049d
+00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 # 0x000004ad
+00 08 00 00 00 00 00 00 00 00 00 00 00 00 00 00 # 0x000004bd
 
-# offset 0x000004bd: page record, payload 119 bytes
-03 00 77 00 00 00 84 a6 e9 08 02 00 03 00 00 00 # 0x000004bd
-00 00 80 00 c0 00 00 02 00 00 00 08 00 00 03 00 # 0x000004cd
-00 00 00 00 00 00 00 72 00 00 00 00 00 00 00 00 # 0x000004dd
-00 00 00 00 00 00 00 6e 00 00 00 00 00 00 00 03 # 0x000004ed
-00 00 00 00 00 00 00 00 61 00 00 00 00 00 00 00 # 0x000004fd
-00 00 00 00 00 00 00 00 74 00 00 00 00 00 00 00 # 0x0000050d
-03 00 00 00 00 00 00 00 00 65 00 00 00 00 00 00 # 0x0000051d
-00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 # 0x0000052d
-00 # 0x0000053d
+# offset 0x000004cd: page record, payload 119 bytes
+03 00 77 00 00 00 84 a6 e9 08 02 00 03 00 00 00 # 0x000004cd
+00 00 80 00 c0 00 00 02 00 00 00 08 00 00 03 00 # 0x000004dd
+00 00 00 00 00 00 00 72 00 00 00 00 00 00 00 00 # 0x000004ed
+00 00 00 00 00 00 00 6e 00 00 00 00 00 00 00 03 # 0x000004fd
+00 00 00 00 00 00 00 00 61 00 00 00 00 00 00 00 # 0x0000050d
+00 00 00 00 00 00 00 00 74 00 00 00 00 00 00 00 # 0x0000051d
+03 00 00 00 00 00 00 00 00 65 00 00 00 00 00 00 # 0x0000052d
+00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 # 0x0000053d
+00 # 0x0000054d
 
-# offset 0x0000053e: ready record, payload 32 bytes
-05 00 20 00 00 00 29 ce 51 e1 28 ab 80 18 19 00 # 0x0000053e
-ef b3 15 fa 9d 03 c3 42 7f 77 2d f3 0c 00 87 cc # 0x0000054e
-a1 dc ac ce 6c fc fb 27 66 e1 # 0x0000055e
+# offset 0x0000054e: ready record, payload 32 bytes
+05 00 20 00 00 00 43 0d 7b 3a 84 06 56 ba 02 59 # 0x0000054e
+04 24 20 59 96 92 14 ba 76 53 80 40 09 12 85 a7 # 0x0000055e
+f2 b5 b8 f9 63 98 e8 dc 9a 39 # 0x0000056e
 
-# offset 0x00000568: history record, payload 16 bytes
-04 00 10 00 00 00 cc 85 a3 b6 00 00 02 00 00 00 # 0x00000568
-04 00 00 00 00 00 00 00 00 00 # 0x00000578
+# offset 0x00000578: history record, payload 6 bytes
+04 00 06 00 00 00 20 32 ed e1 00 00 02 00 00 00 # 0x00000578
 
-# offset 0x00000582: page record, payload 86 bytes
-03 00 56 00 00 00 52 3b 6e 8d 02 00 02 00 00 00 # 0x00000582
-00 00 10 00 c0 00 00 04 00 00 00 08 00 00 00 00 # 0x00000592
-00 00 00 00 00 00 00 42 00 00 00 00 00 00 00 00 # 0x000005a2
-00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 # 0x000005b2
-00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 # 0x000005c2
-00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 # 0x000005d2
+# offset 0x00000588: page record, payload 86 bytes
+03 00 56 00 00 00 52 3b 6e 8d 02 00 02 00 00 00 # 0x00000588
+00 00 10 00 c0 00 00 04 00 00 00 08 00 00 00 00 # 0x00000598
+00 00 00 00 00 00 00 42 00 00 00 00 00 00 00 00 # 0x000005a8
+00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 # 0x000005b8
+00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 # 0x000005c8
+00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 # 0x000005d8
 
-# offset 0x000005e2: page record, payload 86 bytes
-03 00 56 00 00 00 fb bc 15 06 02 00 02 00 00 00 # 0x000005e2
-00 00 10 00 c0 00 00 04 00 00 00 08 00 00 00 00 # 0x000005f2
-00 00 00 00 00 00 00 41 00 00 00 00 00 00 00 00 # 0x00000602
-00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 # 0x00000612
-00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 # 0x00000622
-00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 # 0x00000632
+# offset 0x000005e8: page record, payload 86 bytes
+03 00 56 00 00 00 fb bc 15 06 02 00 02 00 00 00 # 0x000005e8
+00 00 10 00 c0 00 00 04 00 00 00 08 00 00 00 00 # 0x000005f8
+00 00 00 00 00 00 00 41 00 00 00 00 00 00 00 00 # 0x00000608
+00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 # 0x00000618
+00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 # 0x00000628
+00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 # 0x00000638
 
-# offset 0x00000642: history record, payload 16 bytes
-04 00 10 00 00 00 39 57 cc cf 01 00 00 00 00 00 # 0x00000642
-00 00 00 00 00 00 00 00 00 00 # 0x00000652
+# offset 0x00000648: history record, payload 6 bytes
+04 00 06 00 00 00 b8 7a ba b1 01 00 00 00 00 00 # 0x00000648
 
-# offset 0x0000065c: finish record, payload 32 bytes
-06 00 20 00 00 00 05 71 15 22 3e 4d e9 7a c1 02 # 0x0000065c
-0b a3 6a 10 a0 88 1c 07 03 2c 68 52 15 be 76 d0 # 0x0000066c
-4c a9 a6 2b fd f4 ac 49 62 2b # 0x0000067c
+# offset 0x00000658: finish record, payload 32 bytes
+06 00 20 00 00 00 8d d6 46 7a ac 02 c8 09 9d 1a # 0x00000658
+5a 00 ce 47 5e d7 b0 ae 54 10 bb 0d f1 35 7c ab # 0x00000668
+92 fd ae d3 5e 1a 77 1e 40 7f # 0x00000678
diff --git a/src/terminal/snapshot/testdata/history-header-v1.hex b/src/terminal/snapshot/testdata/history-header-v1.hex
index 6e44379dc..dc8333e5b 100644
--- a/src/terminal/snapshot/testdata/history-header-v1.hex
+++ b/src/terminal/snapshot/testdata/history-header-v1.hex
@@ -7,4 +7,4 @@
 # On mismatch, the candidate is copied to the repository root.
 
 # offset 0x00000000: encoded bytes
-01 00 04 03 02 01 08 07 06 05 04 03 02 01 0a 09 # 0x00000000
+01 00 04 03 02 01 # 0x00000000
diff --git a/src/terminal/snapshot/testdata/screen-header-v1.hex b/src/terminal/snapshot/testdata/screen-header-v1.hex
index 950d5736b..7a29df76c 100644
--- a/src/terminal/snapshot/testdata/screen-header-v1.hex
+++ b/src/terminal/snapshot/testdata/screen-header-v1.hex
@@ -7,6 +7,7 @@
 # On mismatch, the candidate is copied to the repository root.
 
 # offset 0x00000000: encoded bytes
-01 00 03 02 05 04 07 06 03 19 00 00 00 00 01 7f # 0x00000000
-00 00 02 12 34 56 ff 03 00 00 0d 0c 0b 0a e4 3d # 0x00000010
-02 07 01 02 04 08 10 1f 00 11 02 03 01 # 0x00000020
+01 00 03 02 08 07 06 05 04 03 02 01 05 04 07 06 # 0x00000000
+03 19 00 00 00 00 01 7f 00 00 02 12 34 56 ff 03 # 0x00000010
+00 00 0d 0c 0b 0a e4 3d 02 07 01 02 04 08 10 1f # 0x00000020
+00 11 02 03 01 # 0x00000030
diff --git a/src/terminal/snapshot/verify-kaitai.py b/src/terminal/snapshot/verify-kaitai.py
index 1a88ab41c..fb3c750fe 100755
--- a/src/terminal/snapshot/verify-kaitai.py
+++ b/src/terminal/snapshot/verify-kaitai.py
@@ -256,19 +256,14 @@ def validate_complete_snapshot(snapshot: Any, data: bytes) -> None:
                 "the active area"
             )
         overlap_rows = screen_rows - terminal_header.rows
-        if payload.screen_overlap_rows != overlap_rows:
-            raise ValueError(
-                f"HISTORY key {payload.key}: screen_overlap_rows "
-                f"{payload.screen_overlap_rows} does not match {overlap_rows}"
-            )
-
-        total_rows = payload.screen_overlap_rows + sum(
+        history_rows = overlap_rows + sum(
             page.payload.header.rows for page in sequence.pages
         )
-        if total_rows != payload.total_rows:
+        if history_rows != screen.screen.payload.header.history_rows:
             raise ValueError(
-                f"HISTORY key {payload.key}: total_rows "
-                f"{payload.total_rows} does not match {total_rows}"
+                f"SCREEN key {payload.key}: history_rows "
+                f"{screen.screen.payload.header.history_rows} "
+                f"does not match {history_rows}"
             )
 
     for record in all_snapshot_records(snapshot):