diff --git a/arch/s390/include/asm/vdso.h b/arch/s390/include/asm/vdso.h
index ae6261ef97d558bb8d52e38286503ed13fca8373..169d7604eb804432e179b74f2737acc8266fb92a 100644
--- a/arch/s390/include/asm/vdso.h
+++ b/arch/s390/include/asm/vdso.h
@@ -46,6 +46,7 @@ struct vdso_per_cpu_data {
 };
 
 extern struct vdso_data *vdso_data;
+extern struct vdso_data boot_vdso_data;
 
 void vdso_alloc_boot_cpu(struct lowcore *lowcore);
 int vdso_alloc_per_cpu(struct lowcore *lowcore);