diff --git a/client/ts/src/constants.ts b/client/ts/src/constants.ts
index e7d972d94..48c109ee3 100644
--- a/client/ts/src/constants.ts
+++ b/client/ts/src/constants.ts
@@ -1,3 +1,3 @@
-export const FIXED_MANIFEST_HEADER_SIZE: number = 512;
+export const FIXED_MANIFEST_HEADER_SIZE: number = 256;
 export const FIXED_WRAPPER_HEADER_SIZE: number = 64;
 export const NIL = 4_294_967_295;
diff --git a/client/ts/src/market.ts b/client/ts/src/market.ts
index 0a35bedb5..8e7af93fa 100644
--- a/client/ts/src/market.ts
+++ b/client/ts/src/market.ts
@@ -349,8 +349,7 @@ export class Market {
     offset += 4;
 
     // _padding2: [u32; 3],
-    // _padding3: [u64; 32],
-    // _padding4: [u64; 8],
+    // _padding3: [u64; 8],
 
     const bids: RestingOrder[] =
       bidsRootIndex != NIL
diff --git a/programs/manifest/src/state/constants.rs b/programs/manifest/src/state/constants.rs
index 8cafc7b20..d73d8a8a3 100644
--- a/programs/manifest/src/state/constants.rs
+++ b/programs/manifest/src/state/constants.rs
@@ -1,6 +1,6 @@
 use hypertree::RBTREE_OVERHEAD_BYTES;
 
-pub const MARKET_FIXED_SIZE: usize = 512;
+pub const MARKET_FIXED_SIZE: usize = 256;
 pub const GLOBAL_FIXED_SIZE: usize = 88;
 
 // Red black tree overhead is 16 bytes. If each block is 80 bytes, then we get
diff --git a/programs/manifest/src/state/market.rs b/programs/manifest/src/state/market.rs
index 742ba68ba..3e8eb24a5 100644
--- a/programs/manifest/src/state/market.rs
+++ b/programs/manifest/src/state/market.rs
@@ -107,9 +107,11 @@ pub struct MarketFixed {
     /// LinkedList representing all free blocks that could be used for ClaimedSeats or RestingOrders
     free_list_head_index: DataIndex,
 
+    // Unused padding. Saved in case a later version wants to be backwards
+    // compatible. Also, it is nice to have the fixed size be a round number,
+    // 256 bytes.
     _padding2: [u32; 3],
-    _padding3: [u64; 32],
-    _padding4: [u64; 8],
+    _padding3: [u64; 8],
 }
 const_assert_eq!(
     size_of::<MarketFixed>(),
@@ -134,7 +136,6 @@ const_assert_eq!(
     4 +   // claimed_seats_best_index
     4 +   // free_list_head_index
     8 +   // padding2
-    256 + // padding3
     64 // padding4
 );
 const_assert_eq!(size_of::<MarketFixed>(), MARKET_FIXED_SIZE);
@@ -169,8 +170,7 @@ impl MarketFixed {
             claimed_seats_root_index: NIL,
             free_list_head_index: NIL,
             _padding2: [0; 3],
-            _padding3: [0; 32],
-            _padding4: [0; 8],
+            _padding3: [0; 8],
         }
     }