diff --git a/net/core/filter.c b/net/core/filter.c
index 7a0741391353..dc89c3424718 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -82,6 +82,9 @@
 #include <net/mptcp.h>
 #include <net/netfilter/nf_conntrack_bpf.h>
 
+/* Keep the struct bpf_fib_lookup small so that it fits into a cacheline */
+static_assert(sizeof(struct bpf_fib_lookup) == 64, "struct bpf_fib_lookup size check");
+
 static const struct bpf_func_proto *
 bpf_sk_base_func_proto(enum bpf_func_id func_id);