diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index 94ce082..89d3d8a 100644
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -1548,7 +1548,7 @@
 int xfrm_policy_flush(struct net *net, u8 type, struct xfrm_audit *audit_info);
 u32 xfrm_get_acqseq(void);
 extern int xfrm_alloc_spi(struct xfrm_state *x, u32 minspi, u32 maxspi);
-struct xfrm_state *xfrm_find_acq(struct net *net, struct xfrm_mark *mark,
+struct xfrm_state *xfrm_find_acq(struct net *net, const struct xfrm_mark *mark,
 				 u8 mode, u32 reqid, u8 proto,
 				 const xfrm_address_t *daddr,
 				 const xfrm_address_t *saddr, int create,