diff --git a/arch/powerpc/include/asm/thread_info.h b/arch/powerpc/include/asm/thread_info.h
index 4a12c00f8de3..5964145db03d 100644
--- a/arch/powerpc/include/asm/thread_info.h
+++ b/arch/powerpc/include/asm/thread_info.h
@@ -70,6 +70,7 @@ static inline struct thread_info *current_thread_info(void)
 	return (struct thread_info *)val;
 }
 
+extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
 #endif /* __ASSEMBLY__ */
 
 /*