diff --git a/websocket_client.go b/websocket_client.go
index 995f837..81176d0 100644
--- a/websocket_client.go
+++ b/websocket_client.go
@@ -67,6 +67,9 @@ type WebSocketClientOpts struct {
 	// HandShakeTimeout specifies the amount of time allowed to complete the
 	// WebSocket handshake.
 	HandShakeTimeout time.Duration
+	// RequestHeaders specifies the headers to be sent with the WebSocket
+	// handshake.
+	RequestHeaders map[string][]string
 	// ServerURL specifies the WebSocket server URL.
 	ServerURL url.URL
 	// TLSConfig specifies the TLS configuration for the WebSocketClient.
@@ -75,8 +78,9 @@ type WebSocketClientOpts struct {
 
 // WebSocketClient is the client instance for a WebSocket.
 type WebSocketClient struct {
-	handler   WebSocketClientEventHandler
-	serverURL url.URL
+	handler        WebSocketClientEventHandler
+	requestHeaders http.Header
+	serverURL      url.URL
 
 	dialer      websocket.Dialer
 	isConnected bool
@@ -101,8 +105,9 @@ func NewWebSocketClient(opts WebSocketClientOpts) (*WebSocketClient, error) {
 	}
 
 	return &WebSocketClient{
-		serverURL: opts.ServerURL,
-		handler:   opts.Handler,
+		serverURL:      opts.ServerURL,
+		handler:        opts.Handler,
+		requestHeaders: opts.RequestHeaders,
 
 		dialer:      dialer,
 		isConnected: false,
@@ -110,7 +115,7 @@ func NewWebSocketClient(opts WebSocketClientOpts) (*WebSocketClient, error) {
 }
 
 func (c *WebSocketClient) Run(ctx context.Context) error {
-	conn, resp, err := c.dialer.Dial(c.serverURL.String(), nil)
+	conn, resp, err := c.dialer.Dial(c.serverURL.String(), c.requestHeaders)
 	if err != nil {
 		if resp != nil {
 			return fmt.Errorf("unable to connect to server URL at %s (%s): %w", c.serverURL.String(), resp.Status, err)
diff --git a/websocket_client_test.go b/websocket_client_test.go
index d619b74..08fae45 100644
--- a/websocket_client_test.go
+++ b/websocket_client_test.go
@@ -47,7 +47,10 @@ func createWebSocketClient(t *testing.T, serverURL url.URL, enableTLS bool) *web
 
 	handler := Mock[ankh.WebSocketClientEventHandler]()
 	client, err := ankh.NewWebSocketClient(ankh.WebSocketClientOpts{
-		ServerURL:        serverURL,
+		ServerURL: serverURL,
+		RequestHeaders: map[string][]string{
+			"X-Custom-Header": {"custom-value"},
+		},
 		Handler:          handler,
 		HandShakeTimeout: 5 * time.Second,
 		TLSConfig:        tlsConfig,
@@ -117,7 +120,8 @@ func TestWebSocketClient(t *testing.T) {
 			server := createWebSocketServer(t, tt.withTLS)
 			serverHandler := server.mockHandlers[0]
 			captorServerSession := Captor[*ankh.Session]()
-			When(serverHandler.OnConnectionHandler(Any[http.ResponseWriter](), Any[*http.Request]())).ThenReturn("client-key", nil)
+			captorServerRequest := Captor[*http.Request]()
+			When(serverHandler.OnConnectionHandler(Any[http.ResponseWriter](), captorServerRequest.Capture())).ThenReturn("client-key", nil)
 			WhenSingle(serverHandler.OnConnectedHandler(Exact("client-key"), captorServerSession.Capture())).ThenReturn(nil)
 			defer server.cancel()
 
@@ -129,6 +133,10 @@ func TestWebSocketClient(t *testing.T) {
 			handler := client.mockHandler
 			defer client.cancel()
 
+			t.Log("verify client connection request headers are sent to the server")
+			waitForCapture(t, captorServerRequest)
+			require.Equal(t, "custom-value", captorServerRequest.Last().Header.Get("X-Custom-Header"))
+
 			t.Log("obtain server session for further client testing")
 			waitForCapture(t, captorServerSession)
 			serverSession := captorServerSession.Last()
diff --git a/websocket_server_test.go b/websocket_server_test.go
index 92d4b7f..97c21f5 100644
--- a/websocket_server_test.go
+++ b/websocket_server_test.go
@@ -137,7 +137,7 @@ func waitFor(t *testing.T) {
 func waitForCapture[T any](t *testing.T, captor matchers.ArgumentCaptor[T]) {
 	t.Helper()
 
-	defaultWaitForCapture := 10 * time.Millisecond
+	defaultWaitForCapture := 100 * time.Millisecond
 	waitForCapturStr := os.Getenv("ANKH_TEST_WAIT_FOR_CAPTURE")
 	waitForCapture := defaultWaitForCapture
 	if len(waitForCapturStr) != 0 {