diff --git a/include/net/route.h b/include/net/route.h
index 188b8936..f7ce625 100644
--- a/include/net/route.h
+++ b/include/net/route.h
@@ -135,7 +135,7 @@
 
 #define IPTOS_RT_MASK	(IPTOS_TOS_MASK & ~3)
 
-extern __u8 ip_tos2prio[16];
+extern const __u8 ip_tos2prio[16];
 
 static inline char rt_tos2priority(u8 tos)
 {
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 8528502..88fa648 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -167,7 +167,7 @@
 
 #define ECN_OR_COST(class)	TC_PRIO_##class
 
-__u8 ip_tos2prio[16] = {
+const __u8 ip_tos2prio[16] = {
 	TC_PRIO_BESTEFFORT,
 	ECN_OR_COST(FILLER),
 	TC_PRIO_BESTEFFORT,