diff --git a/unix/linux/types.go b/unix/linux/types.go
index 7cb495f0..f8ad099a 100644
--- a/unix/linux/types.go
+++ b/unix/linux/types.go
@@ -3600,8 +3600,12 @@ type FsverityEnableArg C.struct_fsverity_enable_arg
 
 type Nhmsg C.struct_nhmsg
 
+const SizeofNhmsg = C.sizeof_struct_nhmsg
+
 type NexthopGrp C.struct_nexthop_grp
 
+const SizeofNexthopGrp = C.sizeof_struct_nexthop_grp
+
 const (
 	NHA_UNSPEC     = C.NHA_UNSPEC
 	NHA_ID         = C.NHA_ID
diff --git a/unix/ztypes_linux.go b/unix/ztypes_linux.go
index 23cea755..c1a46701 100644
--- a/unix/ztypes_linux.go
+++ b/unix/ztypes_linux.go
@@ -3590,6 +3590,8 @@ type Nhmsg struct {
 	Flags    uint32
 }
 
+const SizeofNhmsg = 0x8
+
 type NexthopGrp struct {
 	Id     uint32
 	Weight uint8
@@ -3597,6 +3599,8 @@ type NexthopGrp struct {
 	Resvd2 uint16
 }
 
+const SizeofNexthopGrp = 0x8
+
 const (
 	NHA_UNSPEC     = 0x0
 	NHA_ID         = 0x1