jonkelling
diff --git a/‎src/Npgsql/NpgsqlDataReader.cs‎
Lines changed: 3 additions & 0 deletions b/‎src/Npgsql/NpgsqlDataReader.cs‎
Lines changed: 3 additions & 0 deletions
diff --git a/‎test/Npgsql.Tests/CopyTests.cs‎
Lines changed: 14 additions & 2 deletions b/‎test/Npgsql.Tests/CopyTests.cs‎
Lines changed: 14 additions & 2 deletions
@@ -491,6 +491,9 @@ async Task<bool> NextResult(bool async, bool isConsuming = false, CancellationTo
                         throw Connector.Break(new NotSupportedException(
                             "COPY isn't supported in regular command execution - see https://www.npgsql.org/doc/copy.html for documentation on COPY with Npgsql. " +
                             "If you are trying to execute a SQL script created by pg_dump, pass the '--inserts' switch to disable generating COPY statements."));
+                    case BackendMessageCode.CopyOutResponse:
+                        throw Connector.Break(new NotSupportedException(
+                            "COPY isn't supported in regular command execution - see https://www.npgsql.org/doc/copy.html for documentation on COPY with Npgsql."));
                     default:
                         throw Connector.UnexpectedMessageReceived(msg.Code);
                     }
 
@@ -1085,17 +1085,29 @@ public async Task Within_transaction()
     }
 
     [Test, IssueLink("https://github.com/npgsql/npgsql/issues/4199")]
-    public async Task Copy_is_not_supported_in_regular_command_execution()
+    public async Task Copy_from_is_not_supported_in_regular_command_execution()
     {
         // Run in a separate pool to protect other queries in multiplexing
         // because we're going to break the connection on CopyInResponse
         await using var dataSource = CreateDataSource();
-        using var conn = await dataSource.OpenConnectionAsync();
+        await using var conn = await dataSource.OpenConnectionAsync();
         var table = await CreateTempTable(conn, "foo INT");
 
         Assert.That(() => conn.ExecuteNonQuery($@"COPY {table} (foo) FROM stdin"), Throws.Exception.TypeOf<NotSupportedException>());
     }
 
+    [Test, IssueLink("https://github.com/npgsql/npgsql/issues/4974")]
+    public async Task Copy_to_is_not_supported_in_regular_command_execution()
+    {
+        // Run in a separate pool to protect other queries in multiplexing
+        // because we're going to break the connection on CopyInResponse
+        await using var dataSource = CreateDataSource();
+        await using var conn = await dataSource.OpenConnectionAsync();
+        var table = await CreateTempTable(conn, "foo INT");
+
+        Assert.That(() => conn.ExecuteNonQuery($@"COPY {table} (foo) TO stdin"), Throws.Exception.TypeOf<NotSupportedException>());
+    }
+
     #endregion
 
     #region Utils