diff --git a/src/Plugins/RocksDBStore/Plugins/Storage/Options.cs b/src/Plugins/RocksDBStore/Plugins/Storage/Options.cs
index 5b70fcdbef..46cb66fa8c 100644
--- a/src/Plugins/RocksDBStore/Plugins/Storage/Options.cs
+++ b/src/Plugins/RocksDBStore/Plugins/Storage/Options.cs
@@ -16,13 +16,13 @@ namespace Neo.Plugins.Storage
     public static class Options
     {
         public static readonly DbOptions Default = CreateDbOptions();
-        public static readonly ReadOptions ReadDefault = new ReadOptions();
-        public static readonly WriteOptions WriteDefault = new WriteOptions();
+        public static readonly ReadOptions ReadDefault = new();
+        public static readonly WriteOptions WriteDefault = new();
         public static readonly WriteOptions WriteDefaultSync = new WriteOptions().SetSync(true);
 
         public static DbOptions CreateDbOptions()
         {
-            DbOptions options = new DbOptions();
+            var options = new DbOptions();
             options.SetCreateMissingColumnFamilies(true);
             options.SetCreateIfMissing(true);
             options.SetErrorIfExists(false);
diff --git a/src/Plugins/RocksDBStore/Plugins/Storage/Snapshot.cs b/src/Plugins/RocksDBStore/Plugins/Storage/Snapshot.cs
index cba1cc2942..95c8c3ccb6 100644
--- a/src/Plugins/RocksDBStore/Plugins/Storage/Snapshot.cs
+++ b/src/Plugins/RocksDBStore/Plugins/Storage/Snapshot.cs
@@ -13,6 +13,7 @@
 using RocksDbSharp;
 using System;
 using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
 
 namespace Neo.Plugins.Storage
 {
@@ -21,43 +22,43 @@ namespace Neo.Plugins.Storage
     /// </summary>
     internal class Snapshot : ISnapshot
     {
-        private readonly RocksDb db;
-        private readonly RocksDbSharp.Snapshot snapshot;
-        private readonly WriteBatch batch;
-        private readonly ReadOptions options;
+        private readonly RocksDb _db;
+        private readonly RocksDbSharp.Snapshot _snapshot;
+        private readonly WriteBatch _batch;
+        private readonly ReadOptions _options;
 
         public Snapshot(RocksDb db)
         {
-            this.db = db;
-            snapshot = db.CreateSnapshot();
-            batch = new WriteBatch();
+            _db = db;
+            _snapshot = db.CreateSnapshot();
+            _batch = new WriteBatch();
 
-            options = new ReadOptions();
-            options.SetFillCache(false);
-            options.SetSnapshot(snapshot);
+            _options = new ReadOptions();
+            _options.SetFillCache(false);
+            _options.SetSnapshot(_snapshot);
         }
 
         public void Commit()
         {
-            db.Write(batch, Options.WriteDefault);
+            _db.Write(_batch, Options.WriteDefault);
         }
 
         public void Delete(byte[] key)
         {
-            batch.Delete(key);
+            _batch.Delete(key);
         }
 
         public void Put(byte[] key, byte[] value)
         {
-            batch.Put(key, value);
+            _batch.Put(key, value);
         }
 
         /// <inheritdoc/>
-        public IEnumerable<(byte[] Key, byte[] Value)> Seek(byte[] keyOrPrefix, SeekDirection direction)
+        public IEnumerable<(byte[] Key, byte[] Value)> Seek(byte[]? keyOrPrefix, SeekDirection direction)
         {
-            if (keyOrPrefix == null) keyOrPrefix = Array.Empty<byte>();
+            keyOrPrefix ??= [];
 
-            using var it = db.NewIterator(readOptions: options);
+            using var it = _db.NewIterator(readOptions: _options);
 
             if (direction == SeekDirection.Forward)
                 for (it.Seek(keyOrPrefix); it.Valid(); it.Next())
@@ -69,24 +70,24 @@ public void Put(byte[] key, byte[] value)
 
         public bool Contains(byte[] key)
         {
-            return db.Get(key, Array.Empty<byte>(), 0, 0, readOptions: options) >= 0;
+            return _db.Get(key, Array.Empty<byte>(), 0, 0, readOptions: _options) >= 0;
         }
 
-        public byte[] TryGet(byte[] key)
+        public byte[]? TryGet(byte[] key)
         {
-            return db.Get(key, readOptions: options);
+            return _db.Get(key, readOptions: _options);
         }
 
-        public bool TryGet(byte[] key, out byte[] value)
+        public bool TryGet(byte[] key, [NotNullWhen(true)] out byte[]? value)
         {
-            value = db.Get(key, readOptions: options);
+            value = _db.Get(key, readOptions: _options);
             return value != null;
         }
 
         public void Dispose()
         {
-            snapshot.Dispose();
-            batch.Dispose();
+            _snapshot.Dispose();
+            _batch.Dispose();
         }
     }
 }
diff --git a/src/Plugins/RocksDBStore/Plugins/Storage/Store.cs b/src/Plugins/RocksDBStore/Plugins/Storage/Store.cs
index 09fa63d08a..9891325479 100644
--- a/src/Plugins/RocksDBStore/Plugins/Storage/Store.cs
+++ b/src/Plugins/RocksDBStore/Plugins/Storage/Store.cs
@@ -13,35 +13,36 @@
 using RocksDbSharp;
 using System;
 using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
 using System.IO;
 
 namespace Neo.Plugins.Storage
 {
     internal class Store : IStore
     {
-        private readonly RocksDb db;
+        private readonly RocksDb _db;
 
         public Store(string path)
         {
-            db = RocksDb.Open(Options.Default, Path.GetFullPath(path));
+            _db = RocksDb.Open(Options.Default, Path.GetFullPath(path));
         }
 
         public void Dispose()
         {
-            db.Dispose();
+            _db.Dispose();
         }
 
         public ISnapshot GetSnapshot()
         {
-            return new Snapshot(db);
+            return new Snapshot(_db);
         }
 
         /// <inheritdoc/>
-        public IEnumerable<(byte[] Key, byte[] Value)> Seek(byte[] keyOrPrefix, SeekDirection direction = SeekDirection.Forward)
+        public IEnumerable<(byte[] Key, byte[] Value)> Seek(byte[]? keyOrPrefix, SeekDirection direction = SeekDirection.Forward)
         {
-            if (keyOrPrefix == null) keyOrPrefix = Array.Empty<byte>();
+            keyOrPrefix ??= [];
 
-            using var it = db.NewIterator();
+            using var it = _db.NewIterator();
             if (direction == SeekDirection.Forward)
                 for (it.Seek(keyOrPrefix); it.Valid(); it.Next())
                     yield return (it.Key(), it.Value());
@@ -52,33 +53,33 @@ public ISnapshot GetSnapshot()
 
         public bool Contains(byte[] key)
         {
-            return db.Get(key, Array.Empty<byte>(), 0, 0) >= 0;
+            return _db.Get(key, Array.Empty<byte>(), 0, 0) >= 0;
         }
 
-        public byte[] TryGet(byte[] key)
+        public byte[]? TryGet(byte[] key)
         {
-            return db.Get(key);
+            return _db.Get(key);
         }
 
-        public bool TryGet(byte[] key, out byte[] value)
+        public bool TryGet(byte[] key, [NotNullWhen(true)] out byte[]? value)
         {
-            value = db.Get(key);
+            value = _db.Get(key);
             return value != null;
         }
 
         public void Delete(byte[] key)
         {
-            db.Remove(key);
+            _db.Remove(key);
         }
 
         public void Put(byte[] key, byte[] value)
         {
-            db.Put(key, value);
+            _db.Put(key, value);
         }
 
         public void PutSync(byte[] key, byte[] value)
         {
-            db.Put(key, value, writeOptions: Options.WriteDefaultSync);
+            _db.Put(key, value, writeOptions: Options.WriteDefaultSync);
         }
     }
 }
diff --git a/src/Plugins/RocksDBStore/RocksDBStore.csproj b/src/Plugins/RocksDBStore/RocksDBStore.csproj
index 7a827d382e..b8e10b0c23 100644
--- a/src/Plugins/RocksDBStore/RocksDBStore.csproj
+++ b/src/Plugins/RocksDBStore/RocksDBStore.csproj
@@ -5,6 +5,7 @@
     <PackageId>Neo.Plugins.Storage.RocksDBStore</PackageId>
     <RootNamespace>Neo.Plugins.Storage</RootNamespace>
     <OutputPath>../../../bin/$(PackageId)</OutputPath>
+    <Nullable>enable</Nullable>
   </PropertyGroup>
 
   <ItemGroup>