diff --git a/arch/x86/include/asm/smp.h b/arch/x86/include/asm/smp.h
index 830b9fcb6427..83a4cc074315 100644
--- a/arch/x86/include/asm/smp.h
+++ b/arch/x86/include/asm/smp.h
@@ -22,7 +22,6 @@ extern cpumask_t cpu_callout_map;
 extern cpumask_t cpu_initialized;
 extern cpumask_t cpu_callin_map;
 
-extern void (*mtrr_hook)(void);
 extern void zap_low_mappings(void);
 
 extern int __cpuinit get_local_pda(int cpu);