diff --git a/src/Nethermind/Nethermind.Specs.Test/ChainSpecStyle/ChainSpecBasedSpecProviderTests.cs b/src/Nethermind/Nethermind.Specs.Test/ChainSpecStyle/ChainSpecBasedSpecProviderTests.cs
index 68ec7213f22..bb20e71c486 100644
--- a/src/Nethermind/Nethermind.Specs.Test/ChainSpecStyle/ChainSpecBasedSpecProviderTests.cs
+++ b/src/Nethermind/Nethermind.Specs.Test/ChainSpecStyle/ChainSpecBasedSpecProviderTests.cs
@@ -265,6 +265,10 @@ public void Chiado_loads_properly()
             Assert.AreEqual(ChiadoSpecProvider.Instance.TerminalTotalDifficulty, provider.TerminalTotalDifficulty);
             Assert.AreEqual(BlockchainIds.Chiado, provider.ChainId);
             Assert.AreEqual(BlockchainIds.Chiado, provider.NetworkId);
+            
+            provider.GetSpec((1, ChiadoSpecProvider.ShanghaiTimestamp - 1)).MaxCodeSize.Should().Be(long.MaxValue);
+            provider.GetSpec((1, ChiadoSpecProvider.ShanghaiTimestamp)).MaxCodeSize.Should().Be(24576L);
+            provider.GetSpec((1, ChiadoSpecProvider.ShanghaiTimestamp)).MaxInitCodeSize.Should().Be(2 * 24576L);
         }
 
 
@@ -312,6 +316,8 @@ public void Mainnet_loads_properly()
             };
 
             CompareSpecProviders(mainnet, provider, forkActivationsToTest, CompareSpecsOptions.CheckDifficultyBomb);
+            provider.GetSpec((MainnetSpecProvider.SpuriousDragonBlockNumber, null)).MaxCodeSize.Should().Be(24576L);
+            provider.GetSpec((MainnetSpecProvider.SpuriousDragonBlockNumber, null)).MaxInitCodeSize.Should().Be(2 * 24576L);
 
             Assert.AreEqual(MainnetSpecProvider.LondonBlockNumber, provider.GenesisSpec.Eip1559TransitionBlock);
             Assert.AreEqual(0_000_000, provider.GetSpec((ForkActivation)4_369_999).DifficultyBombDelay);
diff --git a/src/Nethermind/Nethermind.Specs/ChainSpecStyle/ChainSpecLoader.cs b/src/Nethermind/Nethermind.Specs/ChainSpecStyle/ChainSpecLoader.cs
index 607d324dc64..307b4e907ce 100644
--- a/src/Nethermind/Nethermind.Specs/ChainSpecStyle/ChainSpecLoader.cs
+++ b/src/Nethermind/Nethermind.Specs/ChainSpecStyle/ChainSpecLoader.cs
@@ -97,6 +97,7 @@ private void LoadParameters(ChainSpecJson chainSpecJson, ChainSpec chainSpec)
             MinGasLimit = chainSpecJson.Params.MinGasLimit ?? 5000,
             MaxCodeSize = chainSpecJson.Params.MaxCodeSize,
             MaxCodeSizeTransition = chainSpecJson.Params.MaxCodeSizeTransition,
+            MaxCodeSizeTransitionTimestamp = chainSpecJson.Params.MaxCodeSizeTransitionTimestamp,
             Registrar = chainSpecJson.Params.EnsRegistrar,
             ForkBlock = chainSpecJson.Params.ForkBlock,
             ForkCanonHash = chainSpecJson.Params.ForkCanonHash,
diff --git a/src/Nethermind/Nethermind.Specs/ChainSpecStyle/Json/ChainSpecParamsJson.cs b/src/Nethermind/Nethermind.Specs/ChainSpecStyle/Json/ChainSpecParamsJson.cs
index 2f42d69e61a..c29def202d8 100644
--- a/src/Nethermind/Nethermind.Specs/ChainSpecStyle/Json/ChainSpecParamsJson.cs
+++ b/src/Nethermind/Nethermind.Specs/ChainSpecStyle/Json/ChainSpecParamsJson.cs
@@ -50,6 +50,8 @@ internal class ChainSpecParamsJson
 
         public long? MaxCodeSizeTransition { get; set; }
 
+        public ulong? MaxCodeSizeTransitionTimestamp { get; set; }
+
         public long? Eip140Transition { get; set; }
 
         public long? Eip211Transition { get; set; }