diff --git a/arch/mips/rb532/prom.c b/arch/mips/rb532/prom.c
index c5d8868e1b15..46ca24dbcc2d 100644
--- a/arch/mips/rb532/prom.c
+++ b/arch/mips/rb532/prom.c
@@ -37,8 +37,6 @@
 #include <asm/mach-rc32434/ddr.h>
 #include <asm/mach-rc32434/prom.h>
 
-extern void __init setup_serial_port(void);
-
 unsigned int idt_cpu_freq = 132000000;
 EXPORT_SYMBOL(idt_cpu_freq);