diff --git a/uart-bridge.c b/uart-bridge.c
index 3bbd4a4..aebbdf6 100644
--- a/uart-bridge.c
+++ b/uart-bridge.c
@@ -267,6 +267,8 @@ int main(void)
 {
 	int itf;
 
+	set_sys_clock_khz(250000, false);
+
 	for (itf = 0; itf < CFG_TUD_CDC; itf++)
 		init_uart_data(itf);