diff --git a/cabal.project b/cabal.project
index f78ed827ac..77242c571e 100644
--- a/cabal.project
+++ b/cabal.project
@@ -59,8 +59,8 @@ if impl(ghc >= 9.10)
 source-repository-package
   type: git
   location: https://github.com/IntersectMBO/ouroboros-network
-  tag: d900a38c55e02f5eed8c8d6d6a4671cd8c5acc6a
-  --sha256: sha256-VVccbWFmd9GlL2N/xNsKtXg2U2asGc4fIX1lLEo+Ar8=
+  tag: 388cc6906b83f41ac2da192b1fd89ab986b4af74
+  --sha256: sha256-LUwryrP5jK+/c4lDitJf/oKg/DqLgbIc68bn83FsHI0=
   subdir:
     cardano-client
     cardano-ping
diff --git a/ouroboros-consensus-cardano/src/byron/Ouroboros/Consensus/Byron/Ledger/Mempool.hs b/ouroboros-consensus-cardano/src/byron/Ouroboros/Consensus/Byron/Ledger/Mempool.hs
index 8200ddf8c1..cb0ca0e5a5 100644
--- a/ouroboros-consensus-cardano/src/byron/Ouroboros/Consensus/Byron/Ledger/Mempool.hs
+++ b/ouroboros-consensus-cardano/src/byron/Ouroboros/Consensus/Byron/Ledger/Mempool.hs
@@ -73,6 +73,7 @@ import           Ouroboros.Consensus.Ledger.Abstract
 import           Ouroboros.Consensus.Ledger.SupportsMempool
 import           Ouroboros.Consensus.Util (ShowProxy (..))
 import           Ouroboros.Consensus.Util.Condense
+import           Ouroboros.Network.SizeInBytes as Network
 
 {-------------------------------------------------------------------------------
   Transactions
diff --git a/ouroboros-consensus-cardano/src/shelley/Ouroboros/Consensus/Shelley/Ledger/Mempool.hs b/ouroboros-consensus-cardano/src/shelley/Ouroboros/Consensus/Shelley/Ledger/Mempool.hs
index ce57f1bb3c..0d3b371566 100644
--- a/ouroboros-consensus-cardano/src/shelley/Ouroboros/Consensus/Shelley/Ledger/Mempool.hs
+++ b/ouroboros-consensus-cardano/src/shelley/Ouroboros/Consensus/Shelley/Ledger/Mempool.hs
@@ -39,7 +39,7 @@ module Ouroboros.Consensus.Shelley.Ledger.Mempool (
 import qualified Cardano.Crypto.Hash as Hash
 import qualified Cardano.Ledger.Allegra.Rules as AllegraEra
 import           Cardano.Ledger.Alonzo.Core (Tx, TxSeq, bodyTxL, eraProtVerLow,
-                     fromTxSeq, ppMaxBBSizeL, ppMaxBlockExUnitsL, sizeTxF)
+                     fromTxSeq, ppMaxBBSizeL, ppMaxBlockExUnitsL, sizeTxF, wireSizeTxF)
 import qualified Cardano.Ledger.Alonzo.Rules as AlonzoEra
 import           Cardano.Ledger.Alonzo.Scripts (ExUnits, ExUnits',
                      pointWiseExUnits, unWrapExUnits)
@@ -146,6 +146,8 @@ instance (ShelleyCompatible proto era, TxLimits (ShelleyBlock proto era))
 
   reapplyTx = reapplyShelleyTx
 
+  wireTxSize (ShelleyTx _ tx) = fromIntegral $ tx ^. wireSizeTxF
+
   txForgetValidated (ShelleyValidatedTx txid vtx) = ShelleyTx txid (SL.extractTx vtx)
 
 mkShelleyTx :: forall era proto. ShelleyBasedEra era => Tx era -> GenTx (ShelleyBlock proto era)
diff --git a/ouroboros-consensus-diffusion/src/ouroboros-consensus-diffusion/Ouroboros/Consensus/Network/NodeToNode.hs b/ouroboros-consensus-diffusion/src/ouroboros-consensus-diffusion/Ouroboros/Consensus/Network/NodeToNode.hs
index d9de522cd7..c090eb8a32 100644
--- a/ouroboros-consensus-diffusion/src/ouroboros-consensus-diffusion/Ouroboros/Consensus/Network/NodeToNode.hs
+++ b/ouroboros-consensus-diffusion/src/ouroboros-consensus-diffusion/Ouroboros/Consensus/Network/NodeToNode.hs
@@ -748,6 +748,7 @@ mkApps kernel Tracers {..} mkCodecs ByteLimits {..} genChainSyncTimeout lopBucke
                    (getSharedTxStateVar kernel)
                    (mapTxSubmissionMempoolReader txForgetValidated
                    $ getMempoolReader (getMempool kernel))
+                   wireTxSize
                    them $ \api ->
                      runServer (newTxSubmissionServer api)
 
diff --git a/ouroboros-consensus/src/ouroboros-consensus/Ouroboros/Consensus/HardFork/Combinator/Mempool.hs b/ouroboros-consensus/src/ouroboros-consensus/Ouroboros/Consensus/HardFork/Combinator/Mempool.hs
index a987cb7c32..67a522f624 100644
--- a/ouroboros-consensus/src/ouroboros-consensus/Ouroboros/Consensus/HardFork/Combinator/Mempool.hs
+++ b/ouroboros-consensus/src/ouroboros-consensus/Ouroboros/Consensus/HardFork/Combinator/Mempool.hs
@@ -109,6 +109,12 @@ instance CanHardFork xs => LedgerSupportsMempool (HardForkBlock xs) where
           (WrapValidatedGenTx vtx)
           tls
 
+  wireTxSize =
+        hcollapse
+      . hcmap proxySingle (K . wireTxSize)
+      . getOneEraGenTx
+      . getHardForkGenTx
+
   txForgetValidated =
         HardForkGenTx
       . OneEraGenTx
diff --git a/ouroboros-consensus/src/ouroboros-consensus/Ouroboros/Consensus/Ledger/Dual.hs b/ouroboros-consensus/src/ouroboros-consensus/Ouroboros/Consensus/Ledger/Dual.hs
index a5dc517634..a3a47bf105 100644
--- a/ouroboros-consensus/src/ouroboros-consensus/Ouroboros/Consensus/Ledger/Dual.hs
+++ b/ouroboros-consensus/src/ouroboros-consensus/Ouroboros/Consensus/Ledger/Dual.hs
@@ -609,6 +609,8 @@ instance Bridge m a => LedgerSupportsMempool (DualBlock m a) where
                                            tickedDualLedgerStateBridge
         }
 
+  wireTxSize    = wireTxSize . dualGenTxMain
+
   txForgetValidated vtx =
       DualGenTx {
           dualGenTxMain   = txForgetValidated vDualGenTxMain
diff --git a/ouroboros-consensus/src/ouroboros-consensus/Ouroboros/Consensus/Ledger/SupportsMempool.hs b/ouroboros-consensus/src/ouroboros-consensus/Ouroboros/Consensus/Ledger/SupportsMempool.hs
index 3a218241f3..a4b228b093 100644
--- a/ouroboros-consensus/src/ouroboros-consensus/Ouroboros/Consensus/Ledger/SupportsMempool.hs
+++ b/ouroboros-consensus/src/ouroboros-consensus/Ouroboros/Consensus/Ledger/SupportsMempool.hs
@@ -37,6 +37,7 @@ import           NoThunks.Class
 import           Ouroboros.Consensus.Block.Abstract
 import           Ouroboros.Consensus.Ledger.Abstract
 import           Ouroboros.Consensus.Ticked
+import           Ouroboros.Network.SizeInBytes as Network
 
 -- | Generalized transaction
 --
@@ -111,6 +112,10 @@ class ( UpdateLedger blk
             -> TickedLedgerState blk
             -> Except (ApplyTxErr blk) (TickedLedgerState blk)
 
+  -- | Return the size of a serialised transaction as it is transmitted
+  -- across the network.
+  wireTxSize :: GenTx blk -> Network.SizeInBytes
+
   -- | Discard the evidence that transaction has been previously validated
   txForgetValidated :: Validated (GenTx blk) -> GenTx blk