diff --git a/connection.go b/connection.go
index 82c56ea..60f9a6b 100644
--- a/connection.go
+++ b/connection.go
@@ -300,7 +300,7 @@ func (c *Connection) close() error {
 		}
 	}
 
-	if c.Opts.ConnectionClosedHandlers != nil && len(c.Opts.ConnectionClosedHandlers) > 0 {
+	if len(c.Opts.ConnectionClosedHandlers) > 0 {
 		for _, handler := range c.Opts.ConnectionClosedHandlers {
 			go handler(c)
 		}
@@ -454,7 +454,7 @@ func (c *Connection) Send(message *iso8583.Message, options ...Option) (*iso8583
 	return resp, err
 }
 
-func (c *Connection) writeMessage(w io.Writer, message *iso8583.Message) error {
+func (c *Connection) writeMessage(message *iso8583.Message) error {
 	if c.Opts.MessageWriter != nil {
 		err := c.Opts.MessageWriter.WriteMessage(c.conn, message)
 		if err != nil {
@@ -577,7 +577,7 @@ func (c *Connection) writeLoop() {
 				c.pendingRequestsMu.Unlock()
 			}
 
-			err = c.writeMessage(c.conn, req.message)
+			err = c.writeMessage(req.message)
 			if err != nil {
 				c.handleError(fmt.Errorf("writing message: %w", err))
 
diff --git a/connection_test.go b/connection_test.go
index 9aaa02f..3b501b0 100644
--- a/connection_test.go
+++ b/connection_test.go
@@ -7,6 +7,7 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"math"
 	"net"
 	"net/http"
 	"sync"
@@ -1348,6 +1349,10 @@ func (m *messageIO) WriteMessage(w io.Writer, message *iso8583.Message) error {
 	}
 
 	// create header with message length
+	if len(rawMessage) > math.MaxUint16 {
+		return fmt.Errorf("message length is out of uint16 range: %d", len(rawMessage))
+	}
+	//nolint:gosec // disable G115 as it's a false positive
 	h := header{
 		Length: uint16(len(rawMessage)),
 	}
diff --git a/pool_test.go b/pool_test.go
index 8fd0dea..11093d4 100644
--- a/pool_test.go
+++ b/pool_test.go
@@ -92,6 +92,7 @@ func TestPool(t *testing.T) {
 		// Then pool builds and connects connections to all servers
 		require.Eventually(t, func() bool {
 			// we expect connectionsCnt counter to be incremented by both servers
+			//nolint:gosec // disable G115
 			return atomic.LoadInt32(&connectionsCnt) == int32(serversToStart)
 		}, 500*time.Millisecond, 50*time.Millisecond, "%d expected connections established, but got %d", serversToStart, atomic.LoadInt32(&connectionsCnt))