diff --git a/lib/std/Io/Threaded.zig b/lib/std/Io/Threaded.zig
index 449f2a3a322769e4da37e316bf6c619ce5b44c58..c07885289925c13db3cc9c41d92df555cb61c18b 100644
--- a/lib/std/Io/Threaded.zig
+++ b/lib/std/Io/Threaded.zig
@@ -5006,6 +5006,9 @@ fn clockToPosix(clock: Io.Clock) posix.clockid_t {
         },
         .boot => switch (native_os) {
             .macos, .ios, .watchos, .tvos => posix.CLOCK.MONOTONIC_RAW,
+            // On freebsd derivatives, use MONOTONIC_FAST as currently there's
+            // no precision tradeoff.
+            .freebsd, .dragonfly => posix.CLOCK.MONOTONIC_FAST,
             else => posix.CLOCK.BOOTTIME,
         },
         .cpu_process => posix.CLOCK.PROCESS_CPUTIME_ID,