diff --git a/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper.Test/ArrayTypesTest.cs b/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper.Test/ArrayTypesTest.cs
index 1949a5b..48614ff 100644
--- a/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper.Test/ArrayTypesTest.cs
+++ b/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper.Test/ArrayTypesTest.cs
@@ -1,5 +1,4 @@
-// Copyright (c) Philipp Wagner. All rights reserved.
-// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
 using System;
 using System.Collections.Generic;
diff --git a/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper.Test/BasicDataTypesTests.cs b/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper.Test/BasicDataTypesTests.cs
index 52ccad2..ac07840 100644
--- a/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper.Test/BasicDataTypesTests.cs
+++ b/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper.Test/BasicDataTypesTests.cs
@@ -1,5 +1,4 @@
-// Copyright (c) Philipp Wagner. All rights reserved.
-// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
 using System;
 using System.Collections.Generic;
diff --git a/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper.Test/Extensions/NpgsqlExtensions.cs b/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper.Test/Extensions/NpgsqlExtensions.cs
index bfeea61..7f1630f 100644
--- a/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper.Test/Extensions/NpgsqlExtensions.cs
+++ b/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper.Test/Extensions/NpgsqlExtensions.cs
@@ -1,4 +1,6 @@
-using System.Collections.Generic;
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+using System.Collections.Generic;
 using Npgsql;
 
 namespace PostgreSQLCopyHelper.Test.Extensions
diff --git a/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper.Test/Issues/Issue1_QuotingTest.cs b/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper.Test/Issues/Issue1_QuotingTest.cs
index e3e77be..d7cf17f 100644
--- a/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper.Test/Issues/Issue1_QuotingTest.cs
+++ b/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper.Test/Issues/Issue1_QuotingTest.cs
@@ -1,5 +1,4 @@
-// Copyright (c) Philipp Wagner. All rights reserved.
-// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
 using System;
 using Npgsql;
diff --git a/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper.Test/Issues/Issue2_MixedCaseEntity_Test.cs b/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper.Test/Issues/Issue2_MixedCaseEntity_Test.cs
index 11db545..9028dde 100644
--- a/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper.Test/Issues/Issue2_MixedCaseEntity_Test.cs
+++ b/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper.Test/Issues/Issue2_MixedCaseEntity_Test.cs
@@ -1,5 +1,4 @@
-// Copyright (c) Philipp Wagner. All rights reserved.
-// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
 using System;
 using Npgsql;
diff --git a/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper.Test/NullableBasicDataTypesTest.cs b/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper.Test/NullableBasicDataTypesTest.cs
index 33cfe7a..99dc852 100644
--- a/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper.Test/NullableBasicDataTypesTest.cs
+++ b/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper.Test/NullableBasicDataTypesTest.cs
@@ -1,5 +1,4 @@
-// Copyright (c) Philipp Wagner. All rights reserved.
-// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
 using System;
 using System.Collections.Generic;
diff --git a/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper.Test/PostgreSQLCopyHelper.Test.csproj b/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper.Test/PostgreSQLCopyHelper.Test.csproj
index cc1f7e2..8887a5b 100644
--- a/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper.Test/PostgreSQLCopyHelper.Test.csproj
+++ b/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper.Test/PostgreSQLCopyHelper.Test.csproj
@@ -8,7 +8,7 @@
   <ItemGroup>
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.2.0" />
     <PackageReference Include="NUnit" Version="3.12.0" />
-    <PackageReference Include="NUnit3TestAdapter" Version="3.14.0" />
+    <PackageReference Include="NUnit3TestAdapter" Version="3.15.0" />
   </ItemGroup>
 
   <ItemGroup>
diff --git a/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper.Test/TransactionalTestBase.cs b/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper.Test/TransactionalTestBase.cs
index b31ca03..b233090 100644
--- a/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper.Test/TransactionalTestBase.cs
+++ b/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper.Test/TransactionalTestBase.cs
@@ -1,5 +1,4 @@
-// Copyright (c) Philipp Wagner. All rights reserved.
-// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
 using Npgsql;
 using NUnit.Framework;
diff --git a/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/Extensions/ArrayTypeExtensions.cs b/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/Extensions/ArrayTypeExtensions.cs
index 8ccdc97..c5f7a54 100644
--- a/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/Extensions/ArrayTypeExtensions.cs
+++ b/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/Extensions/ArrayTypeExtensions.cs
@@ -1,5 +1,4 @@
-// Copyright (c) Philipp Wagner. All rights reserved.
-// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
 using System;
 using NpgsqlTypes;
diff --git a/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/Extensions/BinaryDataTypeExtensions.cs b/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/Extensions/BinaryDataTypeExtensions.cs
index 9e5bf60..f128b6f 100644
--- a/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/Extensions/BinaryDataTypeExtensions.cs
+++ b/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/Extensions/BinaryDataTypeExtensions.cs
@@ -1,5 +1,4 @@
-// Copyright (c) Philipp Wagner. All rights reserved.
-// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
 using System;
 using NpgsqlTypes;
diff --git a/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/Extensions/BitStringTypeExtensions.cs b/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/Extensions/BitStringTypeExtensions.cs
index aef3752..b2b8287 100644
--- a/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/Extensions/BitStringTypeExtensions.cs
+++ b/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/Extensions/BitStringTypeExtensions.cs
@@ -1,5 +1,4 @@
-// Copyright (c) Philipp Wagner. All rights reserved.
-// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
 using System;
 using NpgsqlTypes;
diff --git a/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/Extensions/BooleanTypeExtensions.cs b/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/Extensions/BooleanTypeExtensions.cs
index be74c78..e75533c 100644
--- a/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/Extensions/BooleanTypeExtensions.cs
+++ b/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/Extensions/BooleanTypeExtensions.cs
@@ -1,5 +1,4 @@
-// Copyright (c) Philipp Wagner. All rights reserved.
-// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
 using System;
 using NpgsqlTypes;
diff --git a/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/Extensions/CharacterTypeExtensions.cs b/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/Extensions/CharacterTypeExtensions.cs
index b869703..816f491 100644
--- a/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/Extensions/CharacterTypeExtensions.cs
+++ b/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/Extensions/CharacterTypeExtensions.cs
@@ -1,5 +1,4 @@
-// Copyright (c) Philipp Wagner. All rights reserved.
-// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
 using System;
 using NpgsqlTypes;
diff --git a/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/Extensions/DateTimeTypeExtensions.cs b/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/Extensions/DateTimeTypeExtensions.cs
index 2cc8510..ee9da13 100644
--- a/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/Extensions/DateTimeTypeExtensions.cs
+++ b/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/Extensions/DateTimeTypeExtensions.cs
@@ -1,5 +1,4 @@
-// Copyright (c) Philipp Wagner. All rights reserved.
-// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
 using System;
 using NpgsqlTypes;
diff --git a/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/Extensions/JsonTypeExtension.cs b/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/Extensions/JsonTypeExtension.cs
index fa262c1..ca78ffb 100644
--- a/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/Extensions/JsonTypeExtension.cs
+++ b/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/Extensions/JsonTypeExtension.cs
@@ -1,5 +1,4 @@
-// Copyright (c) Philipp Wagner. All rights reserved.
-// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
 using System;
 using NpgsqlTypes;
diff --git a/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/Extensions/MonetaryTypeExtensions.cs b/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/Extensions/MonetaryTypeExtensions.cs
index 0e66f64..e6f73dc 100644
--- a/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/Extensions/MonetaryTypeExtensions.cs
+++ b/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/Extensions/MonetaryTypeExtensions.cs
@@ -1,5 +1,4 @@
-// Copyright (c) Philipp Wagner. All rights reserved.
-// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
 using System;
 using NpgsqlTypes;
diff --git a/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/Extensions/NetworkAddressTypeExtensions.cs b/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/Extensions/NetworkAddressTypeExtensions.cs
index 153f2e1..3885315 100644
--- a/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/Extensions/NetworkAddressTypeExtensions.cs
+++ b/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/Extensions/NetworkAddressTypeExtensions.cs
@@ -1,5 +1,4 @@
-// Copyright (c) Philipp Wagner. All rights reserved.
-// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
 using System;
 using System.Net;
@@ -20,4 +19,4 @@ public static PostgreSQLCopyHelper<TEntity> MapMacAddress<TEntity>(this PostgreS
             return helper.Map(columnName, propertyGetter, NpgsqlDbType.MacAddr);
         }
     }
-}
\ No newline at end of file
+}
diff --git a/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/Extensions/NumericTypeExtensions.cs b/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/Extensions/NumericTypeExtensions.cs
index 20b3d63..010a68c 100644
--- a/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/Extensions/NumericTypeExtensions.cs
+++ b/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/Extensions/NumericTypeExtensions.cs
@@ -1,5 +1,4 @@
-// Copyright (c) Philipp Wagner. All rights reserved.
-// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
 using System;
 using NpgsqlTypes;
@@ -68,4 +67,4 @@ public static PostgreSQLCopyHelper<TEntity> MapDouble<TEntity>(this PostgreSQLCo
             return helper.MapNullable(columnName, propertyGetter, NpgsqlDbType.Double);
         }
     }
-}
\ No newline at end of file
+}
diff --git a/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/Extensions/UUIDTypeExtensions.cs b/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/Extensions/UUIDTypeExtensions.cs
index 56182c0..214a2f2 100644
--- a/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/Extensions/UUIDTypeExtensions.cs
+++ b/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/Extensions/UUIDTypeExtensions.cs
@@ -1,5 +1,4 @@
-// Copyright (c) Philipp Wagner. All rights reserved.
-// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
 using System;
 using NpgsqlTypes;
diff --git a/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/IPostgreSQLCopyHelper.cs b/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/IPostgreSQLCopyHelper.cs
index 0959282..8b90770 100644
--- a/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/IPostgreSQLCopyHelper.cs
+++ b/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/IPostgreSQLCopyHelper.cs
@@ -1,7 +1,8 @@
-// Copyright (c) Philipp Wagner. All rights reserved.
-// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
 using System.Collections.Generic;
+using System.Threading;
+using System.Threading.Tasks;
 using Npgsql;
 
 namespace PostgreSQLCopyHelper
@@ -9,5 +10,6 @@ namespace PostgreSQLCopyHelper
     public interface IPostgreSQLCopyHelper<TEntity>
     {
         ulong SaveAll(NpgsqlConnection connection, IEnumerable<TEntity> entities);
+        ValueTask<ulong> SaveAllAsync(NpgsqlConnection connection, IEnumerable<TEntity> entities, CancellationToken cancellationToken = default);
     }
 }
diff --git a/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/Model/ColumnDefinition.cs b/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/Model/ColumnDefinition.cs
index 6baf89d..94bc9e6 100644
--- a/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/Model/ColumnDefinition.cs
+++ b/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/Model/ColumnDefinition.cs
@@ -1,7 +1,7 @@
-// Copyright (c) Philipp Wagner. All rights reserved.
-// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
 using System;
+using System.Threading.Tasks;
 using Npgsql;
 
 namespace PostgreSQLCopyHelper.Model
@@ -10,7 +10,7 @@ internal class ColumnDefinition<TEntity>
     {
         public string ColumnName { get; set; }
 
-        public Action<NpgsqlBinaryImporter, TEntity> Write { get; set; }
+        public Func<NpgsqlBinaryImporter, TEntity, Task> Write { get; set; }
 
         public override string ToString()
         {
diff --git a/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/Model/TableDefinition.cs b/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/Model/TableDefinition.cs
index b28bdc6..485015a 100644
--- a/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/Model/TableDefinition.cs
+++ b/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/Model/TableDefinition.cs
@@ -1,5 +1,4 @@
-// Copyright (c) Philipp Wagner. All rights reserved.
-// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
 using PostgreSQLCopyHelper.Utils;
 
diff --git a/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper.cs b/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper.cs
index 24e8007..3b13976 100644
--- a/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper.cs
+++ b/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper.cs
@@ -1,9 +1,10 @@
-// Copyright (c) Philipp Wagner. All rights reserved.
-// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
 using Npgsql;
 using NpgsqlTypes;
 using PostgreSQLCopyHelper.Model;
@@ -37,13 +38,29 @@ public PostgreSQLCopyHelper(string schemaName, string tableName)
             _columns = new List<ColumnDefinition<TEntity>>();
         }
 
-        public ulong SaveAll(NpgsqlConnection connection, IEnumerable<TEntity> entities)
+        public ulong SaveAll(NpgsqlConnection connection, IEnumerable<TEntity> entities) =>
+            DoSaveAllAsync(connection, entities).GetAwaiter().GetResult();
+
+        public ValueTask<ulong> SaveAllAsync(NpgsqlConnection connection, IEnumerable<TEntity> entities, CancellationToken cancellationToken = default)
+        {
+            if (cancellationToken.IsCancellationRequested)
+            {
+                return new ValueTask<ulong>(Task.FromCanceled<ulong>(cancellationToken));
+            }
+
+            using (NoSynchronizationContextScope.Enter())
+            {
+                return DoSaveAllAsync(connection, entities);
+            }
+        }
+
+        private async ValueTask<ulong> DoSaveAllAsync(NpgsqlConnection connection, IEnumerable<TEntity> entities)
         {
             using (var binaryCopyWriter = connection.BeginBinaryImport(GetCopyCommand()))
             {
-                WriteToStream(binaryCopyWriter, entities);
+                await WriteToStream(binaryCopyWriter, entities);
 
-                return binaryCopyWriter.Complete();
+                return await binaryCopyWriter.CompleteAsync();
             }
         }
 
@@ -56,41 +73,41 @@ public PostgreSQLCopyHelper<TEntity> UsePostgresQuoting(bool enabled = true)
 
         public PostgreSQLCopyHelper<TEntity> Map<TProperty>(string columnName, Func<TEntity, TProperty> propertyGetter, NpgsqlDbType type)
         {
-            return AddColumn(columnName, (writer, entity) => writer.Write(propertyGetter(entity), type));
+            return AddColumn(columnName, (writer, entity) => writer.WriteAsync(propertyGetter(entity), type));
         }
 
         public PostgreSQLCopyHelper<TEntity> MapNullable<TProperty>(string columnName, Func<TEntity, TProperty?> propertyGetter, NpgsqlDbType type)
             where TProperty : struct
         {
-            return AddColumn(columnName, (writer, entity) =>
+            return AddColumn(columnName, async (writer, entity) =>
             {
                 var val = propertyGetter(entity);
 
                 if (!val.HasValue)
                 {
-                    writer.WriteNull();
+                    await writer.WriteNullAsync();
                 }
                 else
                 {
-                    writer.Write(val.Value, type);
+                    await writer.WriteAsync(val.Value, type);
                 }
             });
         }
 
-        private void WriteToStream(NpgsqlBinaryImporter writer, IEnumerable<TEntity> entities)
+        private async Task WriteToStream(NpgsqlBinaryImporter writer, IEnumerable<TEntity> entities)
         {
             foreach (var entity in entities)
             {
-                writer.StartRow();
+                await writer.StartRowAsync();
 
                 foreach (var columnDefinition in _columns)
                 {
-                    columnDefinition.Write(writer, entity);
+                    await columnDefinition.Write(writer, entity);
                 }
             }
         }
 
-        private PostgreSQLCopyHelper<TEntity> AddColumn(string columnName, Action<NpgsqlBinaryImporter, TEntity> action)
+        private PostgreSQLCopyHelper<TEntity> AddColumn(string columnName, Func<NpgsqlBinaryImporter, TEntity, Task> action)
         {
             _columns.Add(new ColumnDefinition<TEntity>
             {
diff --git a/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper.csproj b/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper.csproj
index a3b5008..599af68 100644
--- a/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper.csproj
+++ b/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper.csproj
@@ -21,7 +21,11 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Npgsql" Version="4.1.0-preview1" />
+    <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.0.0-beta2-19367-01">
+      <PrivateAssets>all</PrivateAssets>
+      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+    </PackageReference>
+    <PackageReference Include="Npgsql" Version="4.1.0-ci.2184" />
   </ItemGroup>
 
 </Project>
diff --git a/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/Utils/NoSynchronizationContextScope.cs b/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/Utils/NoSynchronizationContextScope.cs
new file mode 100644
index 0000000..3ccc433
--- /dev/null
+++ b/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/Utils/NoSynchronizationContextScope.cs
@@ -0,0 +1,40 @@
+// Code taken from https://github.com/npgsql/npgsql/blob/dev/src/Npgsql/NoSynchronizationContextScope.cs
+
+using System;
+using System.Threading;
+
+namespace PostgreSQLCopyHelper.Utils
+{
+    /// <summary>
+    /// This mechanism is used to temporarily set the current synchronization context to null while
+    /// executing Npgsql code, making all await continuations execute on the thread pool. This replaces
+    /// the need to place ConfigureAwait(false) everywhere, and should be used in all surface async methods,
+    /// without exception.
+    ///
+    /// Warning: do not use this directly in async methods, use it in sync wrappers of async methods
+    /// (see https://github.com/npgsql/npgsql/issues/1593)
+    /// </summary>
+    /// <remarks>
+    /// http://stackoverflow.com/a/28307965/640325
+    /// </remarks>
+    internal static class NoSynchronizationContextScope
+    {
+        internal static Disposable Enter()
+        {
+            var sc = SynchronizationContext.Current;
+            SynchronizationContext.SetSynchronizationContext(null);
+            return new Disposable(sc);
+        }
+
+        internal struct Disposable : IDisposable
+        {
+            private readonly SynchronizationContext _synchronizationContext;
+
+            internal Disposable(SynchronizationContext synchronizationContext)
+                => _synchronizationContext = synchronizationContext;
+
+            public void Dispose()
+                => SynchronizationContext.SetSynchronizationContext(_synchronizationContext);
+        }
+    }
+}
diff --git a/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/Utils/NpgsqlUtils.cs b/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/Utils/NpgsqlUtils.cs
index 803f754..7fa4192 100644
--- a/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/Utils/NpgsqlUtils.cs
+++ b/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/Utils/NpgsqlUtils.cs
@@ -1,5 +1,4 @@
-// Copyright (c) Philipp Wagner. All rights reserved.
-// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
 using System.Linq;
 
diff --git a/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/Utils/StringExtensions.cs b/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/Utils/StringExtensions.cs
index 40d0a39..39c34b5 100644
--- a/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/Utils/StringExtensions.cs
+++ b/PostgreSQLCopyHelper/PostgreSQLCopyHelper/PostgreSQLCopyHelper/Utils/StringExtensions.cs
@@ -1,4 +1,6 @@
-namespace PostgreSQLCopyHelper.Utils
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+namespace PostgreSQLCopyHelper.Utils
 {
     public static class StringExtensions
     {