diff --git a/lib/std/c.zig b/lib/std/c.zig
index fe8989e4b0fc7bc17d78c7fbe3d6e400fc3c847a..fbd0c1d55cbb262347d251dc44699efb05eb674b 100644
--- a/lib/std/c.zig
+++ b/lib/std/c.zig
@@ -222,11 +222,12 @@ pub const ARCH = switch (native_os) {
 // that actually work.
 pub const TIMERFD_CLOCK = timerfd_clockid_t;
 pub const timerfd_clockid_t = switch (native_os) {
-    .linux, .freebsd => enum(u32) {
+    .freebsd => enum(u32) {
         REALTIME = 0,
-        MONOTONIC = 1,
+        MONOTONIC = 4,
         _,
     },
+    .linux => linux.timerfd_clockid_t,
     else => clockid_t,
 };
 
diff --git a/lib/std/os/linux.zig b/lib/std/os/linux.zig
index 1df5882df1bfcfa7cb05a8f7e9599d3abdd4c948..365fb9f05f6bd736450fecb5983e83709478f5f7 100644
--- a/lib/std/os/linux.zig
+++ b/lib/std/os/linux.zig
@@ -4722,6 +4722,9 @@ pub const TIMERFD_CLOCK = timerfd_clockid_t;
 pub const timerfd_clockid_t = enum(u32) {
     REALTIME = 0,
     MONOTONIC = 1,
+    BOOTTIME = 7,
+    REALTIME_ALARM = 8,
+    BOOTTIME_ALARM = 9,
     _,
 };