diff --git a/arch/mips/rb532/serial.c b/arch/mips/rb532/serial.c
index 70482540b3db..228eff07e5e8 100644
--- a/arch/mips/rb532/serial.c
+++ b/arch/mips/rb532/serial.c
@@ -45,7 +45,7 @@ static struct uart_port rb532_uart = {
 	.regshift = 2
 };
 
-int __init setup_serial_port(void)
+static int __init setup_serial_port(void)
 {
 	rb532_uart.uartclk = idt_cpu_freq;