diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 04f07b2f..038180fa 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -143,7 +143,6 @@ jobs:
       fail-fast: false
       matrix:
         tag:
-        - 'yandex/clickhouse-server:20.3'
         - 'yandex/clickhouse-server:20.6'
         - 'yandex/clickhouse-server:20.9'
         - 'yandex/clickhouse-server:20.12'
diff --git a/ClickHouse.Client.Tests/BulkCopyTests.cs b/ClickHouse.Client.Tests/BulkCopyTests.cs
index 91d95df5..d4faf813 100644
--- a/ClickHouse.Client.Tests/BulkCopyTests.cs
+++ b/ClickHouse.Client.Tests/BulkCopyTests.cs
@@ -60,7 +60,7 @@ public async Task ShouldExecuteSingleValueInsertViaBulkCopy(string clickHouseTyp
     public async Task ShouldExecuteMultipleBulkInsertions()
     {
         var sw = new Stopwatch();
-        var duration = new TimeSpan(0, 5, 0);
+        var duration = TimeSpan.FromMinutes(5);
 
         var targetTable = "test." + SanitizeTableName($"bulk_load_test");
 
diff --git a/ClickHouse.Client/Copy/ClickHouseBulkCopy.cs b/ClickHouse.Client/Copy/ClickHouseBulkCopy.cs
index 7fd68293..e850158d 100644
--- a/ClickHouse.Client/Copy/ClickHouseBulkCopy.cs
+++ b/ClickHouse.Client/Copy/ClickHouseBulkCopy.cs
@@ -165,16 +165,21 @@ public async Task WriteToServerAsync(IEnumerable<object[]> rows, IReadOnlyCollec
                 var completedTaskIndex = Array.FindIndex(tasks, t => t.IsCompleted);
                 if (completedTaskIndex >= 0)
                 {
-                    // propagate exception if one happens
-                    // 'await' instead of 'Wait()' to avoid dealing with AggregateException
-                    await tasks[completedTaskIndex].ConfigureAwait(false);
-                    tasks[completedTaskIndex] = connection.PostStreamAsync(useInlineQuery ? null : query, stream, true, token)
-                        .ContinueWith(t => { using (stream) Interlocked.Add(ref rowsWritten, counter); }, token);
+                    async Task SendBatch()
+                    {
+                        using (stream)
+                        {
+                            await connection.PostStreamAsync(useInlineQuery ? null : query, stream, true, token).ConfigureAwait(false);
+                            Interlocked.Add(ref rowsWritten, counter);
+                        }
+                    }
+                    tasks[completedTaskIndex] = SendBatch();
                     break; // while (true); go to next batch
                 }
                 else
                 {
-                    await Task.WhenAny(tasks).ConfigureAwait(false);
+                    var completedTask = await Task.WhenAny(tasks).ConfigureAwait(false);
+                    await completedTask.ConfigureAwait(false);
                 }
             }
         }
@@ -193,5 +198,10 @@ public void Dispose()
         GC.SuppressFinalize(this);
     }
 
+    // Utility method wrapping sending data to ClickHouse and counter increment as a single task
+    private async Task WriteStreamAndIncrement(Stream stream, string query, bool useInlineQuery, int counter, CancellationToken token)
+    {
+    }
+
     private static string GetColumnsExpression(IReadOnlyCollection<string> columns) => columns == null || columns.Count == 0 ? "*" : string.Join(",", columns);
 }