diff --git a/lib/std/c/freebsd.zig b/lib/std/c/freebsd.zig
index 9f02872abe..16653ae47b 100644
--- a/lib/std/c/freebsd.zig
+++ b/lib/std/c/freebsd.zig
@@ -1105,6 +1105,11 @@ pub const DT = struct {
     pub const WHT = 14;
 };
 
+pub const accept_filter = extern struct {
+    af_name: [16]u8,
+    af_args: [240]u8,
+};
+
 /// add event to kq (implies enable)
 pub const EV_ADD = 0x0001;