1 files changed, 1 insertions, 1 deletions

diff --git a/arch/s390/include/asm/system.h b/arch/s390/include/asm/system.h
index 6710b0eac16..8f8d759f6a7 100644
--- a/arch/s390/include/asm/system.h
+++ b/arch/s390/include/asm/system.h
@@ -449,7 +449,7 @@ extern void (*_machine_restart)(char *command);
 extern void (*_machine_halt)(void);
 extern void (*_machine_power_off)(void);
 
-#define arch_align_stack(x) (x)
+extern unsigned long arch_align_stack(unsigned long sp);
 
 static inline int tprot(unsigned long addr)
 {