diff --git a/net/core/filter.c b/net/core/filter.c
index ce255e0a2fbd..15d850ea7d4a 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -87,6 +87,9 @@
 
 #include "dev.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, const struct bpf_prog *prog);