diff --git a/src/Nethermind/Nethermind.DataMarketplace.Infrastructure/NdmApi.cs b/src/Nethermind/Nethermind.DataMarketplace.Infrastructure/NdmApi.cs
index a53ad77b9d8..beed1265a57 100644
--- a/src/Nethermind/Nethermind.DataMarketplace.Infrastructure/NdmApi.cs
+++ b/src/Nethermind/Nethermind.DataMarketplace.Infrastructure/NdmApi.cs
@@ -440,7 +440,7 @@ public ITrieStore? TrieStore
             set => _nethermindApi.TrieStore = value;
         }
         
-        public ITrieStore? ReadOnlyTrieStore
+        public ReadOnlyTrieStore? ReadOnlyTrieStore
         {
             get => _nethermindApi.ReadOnlyTrieStore;
             set => _nethermindApi.ReadOnlyTrieStore = value;
diff --git a/src/Nethermind/Nethermind.Db/IRocksDbFactory.cs b/src/Nethermind/Nethermind.Db/IRocksDbFactory.cs
index cd7d63ca7d8..48741c9e33c 100644
--- a/src/Nethermind/Nethermind.Db/IRocksDbFactory.cs
+++ b/src/Nethermind/Nethermind.Db/IRocksDbFactory.cs
@@ -20,6 +20,6 @@ public interface IRocksDbFactory
     {
         IDb CreateDb(RocksDbSettings rocksDbSettings);
         
-        IColumnsDb<T> CreateColumnsDb<T>(RocksDbSettings rocksDbSettings);
+        IColumnsDb<T> CreateColumnsDb<T>(RocksDbSettings rocksDbSettings) where T : notnull;
     }
 }
diff --git a/src/Nethermind/Nethermind.JsonRpc.Test/Modules/EthModuleTests.cs b/src/Nethermind/Nethermind.JsonRpc.Test/Modules/EthModuleTests.cs
index 859625357dd..5288f03288a 100644
--- a/src/Nethermind/Nethermind.JsonRpc.Test/Modules/EthModuleTests.cs
+++ b/src/Nethermind/Nethermind.JsonRpc.Test/Modules/EthModuleTests.cs
@@ -34,7 +34,6 @@
 using Nethermind.Logging;
 using Nethermind.Serialization.Json;
 using Nethermind.Serialization.Rlp;
-using Nethermind.Trie;
 using Nethermind.TxPool;
 using NSubstitute;
 using NUnit.Framework;
diff --git a/src/Nethermind/Nethermind.JsonRpc.Test/Modules/TransactionForRpcConverterTests.cs b/src/Nethermind/Nethermind.JsonRpc.Test/Modules/TransactionForRpcConverterTests.cs
new file mode 100644
index 00000000000..33a65588eb8
--- /dev/null
+++ b/src/Nethermind/Nethermind.JsonRpc.Test/Modules/TransactionForRpcConverterTests.cs
@@ -0,0 +1,53 @@
+//  Copyright (c) 2021 Demerzel Solutions Limited
+//  This file is part of the Nethermind library.
+// 
+//  The Nethermind library is free software: you can redistribute it and/or modify
+//  it under the terms of the GNU Lesser General Public License as published by
+//  the Free Software Foundation, either version 3 of the License, or
+//  (at your option) any later version.
+// 
+//  The Nethermind library is distributed in the hope that it will be useful,
+//  but WITHOUT ANY WARRANTY; without even the implied warranty of
+//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+//  GNU Lesser General Public License for more details.
+// 
+//  You should have received a copy of the GNU Lesser General Public License
+//  along with the Nethermind. If not, see <http://www.gnu.org/licenses/>.
+
+using System;
+using FluentAssertions;
+using Nethermind.Core;
+using Nethermind.Core.Crypto;
+using Nethermind.JsonRpc.Data;
+using Nethermind.JsonRpc.Test.Data;
+using Nethermind.Serialization.Json;
+using NUnit.Framework;
+
+namespace Nethermind.JsonRpc.Test.Modules
+{
+    [Parallelizable(ParallelScope.Self)]
+    [TestFixture]
+    public class TransactionForRpcConverterTests : SerializationTestBase
+    {
+        [Test]
+        public void R_and_s_are_quantity_and_not_data()
+        {
+            byte[] r = new byte[32];
+            byte[] s = new byte[32];
+            r[1] = 1;
+            s[2] = 2;
+            
+            Transaction tx = new Transaction();
+            tx.Signature = new Signature(r, s, 27);
+            
+            TransactionForRpc txForRpc = new TransactionForRpc(tx);
+
+            EthereumJsonSerializer serializer = new EthereumJsonSerializer();
+            string serialized = serializer.Serialize(txForRpc);
+
+            serialized.Should().Contain("0x20000000000000000000000000000000000000000000000000000000000");
+            serialized.Should().Contain("0x1000000000000000000000000000000000000000000000000000000000000");
+            Console.WriteLine(serialized);
+        }
+    }
+}
diff --git a/src/Nethermind/Nethermind.JsonRpc/Data/TransactionForRpc.cs b/src/Nethermind/Nethermind.JsonRpc/Data/TransactionForRpc.cs
index 24a4ff58389..6acb10fe462 100644
--- a/src/Nethermind/Nethermind.JsonRpc/Data/TransactionForRpc.cs
+++ b/src/Nethermind/Nethermind.JsonRpc/Data/TransactionForRpc.cs
@@ -26,7 +26,7 @@ public class TransactionForRpc
     {
         public TransactionForRpc(Transaction transaction) : this(null, null, null, transaction) { }
         
-        public TransactionForRpc(Keccak blockHash, long? blockNumber, int? txIndex, Transaction transaction)
+        public TransactionForRpc(Keccak? blockHash, long? blockNumber, int? txIndex, Transaction transaction)
         {
             Hash = transaction.Hash;
             Nonce = transaction.Nonce;
@@ -39,9 +39,14 @@ public TransactionForRpc(Keccak blockHash, long? blockNumber, int? txIndex, Tran
             GasPrice = transaction.GasPrice;
             Gas = transaction.GasLimit;
             Input = Data = transaction.Data ?? transaction.Init;
-            R = transaction.Signature?.R;
-            S = transaction.Signature?.S;
-            V = (UInt256?) transaction.Signature?.V;
+
+            Signature? signature = transaction.Signature;
+            if (signature != null)
+            {
+                R = new UInt256(signature.R, true);
+                S = new UInt256(signature.S, true);
+                V = (UInt256?)signature.V;
+            }
         }
 
         // ReSharper disable once UnusedMember.Global
@@ -49,33 +54,33 @@ public TransactionForRpc()
         {
         }
 
-        public Keccak Hash { get; set; }
+        public Keccak? Hash { get; set; }
         public UInt256? Nonce { get; set; }
         
         [JsonProperty(NullValueHandling = NullValueHandling.Include)]
-        public Keccak BlockHash { get; set; }
+        public Keccak? BlockHash { get; set; }
         
         [JsonProperty(NullValueHandling = NullValueHandling.Include)]
         public long? BlockNumber { get; set; }
         
         [JsonProperty(NullValueHandling = NullValueHandling.Include)]
         public long? TransactionIndex { get; set; }
-        public Address From { get; set; }
+        public Address? From { get; set; }
         
         [JsonProperty(NullValueHandling = NullValueHandling.Include)]
-        public Address To { get; set; }
+        public Address? To { get; set; }
         public UInt256? Value { get; set; }
         public UInt256? GasPrice { get; set; }
         public long? Gas { get; set; }
-        public byte[] Data { get; set; }
+        public byte[]? Data { get; set; }
         
         [JsonProperty(NullValueHandling = NullValueHandling.Include)]
-        public byte[] Input { get; set; }
+        public byte[]? Input { get; set; }
         public UInt256? V { get; set; }
 
-        public byte[] S { get; set; }
+        public UInt256? S { get; set; }
 
-        public byte[] R { get; set; }
+        public UInt256? R { get; set; }
 
         public Transaction ToTransactionWithDefaults()
         {
diff --git a/src/Nethermind/Nethermind.JsonRpc/Nethermind.JsonRpc.csproj b/src/Nethermind/Nethermind.JsonRpc/Nethermind.JsonRpc.csproj
index 03d6a67047c..20ad23863b4 100644
--- a/src/Nethermind/Nethermind.JsonRpc/Nethermind.JsonRpc.csproj
+++ b/src/Nethermind/Nethermind.JsonRpc/Nethermind.JsonRpc.csproj
@@ -4,6 +4,7 @@
     <LangVersion>9</LangVersion>
     <Deterministic>true</Deterministic>
     <ProduceReferenceAssembly>true</ProduceReferenceAssembly>
+    <Nullable>enable</Nullable>
   </PropertyGroup>
   <ItemGroup>
     <PackageReference Include="Newtonsoft.Json" Version="12.0.3" />