diff --git a/net/sched/cls_u32.c b/net/sched/cls_u32.c
index e8a7756..b18fa95 100644
--- a/net/sched/cls_u32.c
+++ b/net/sched/cls_u32.c
@@ -82,7 +82,7 @@
 	u32			hgenerator;
 };
 
-static struct tcf_ext_map u32_ext_map = {
+static const struct tcf_ext_map u32_ext_map = {
 	.action = TCA_U32_ACT,
 	.police = TCA_U32_POLICE
 };