diff --git a/src/misc.c b/src/misc.c
index 4db2d9a4..bf50b00b 100644
--- a/src/misc.c
+++ b/src/misc.c
@@ -577,3 +577,61 @@ _gcry_divide_by_zero (void)
     gpg_err_set_errno (EDOM);
     _gcry_fatal_error (gpg_err_code_from_errno (errno), "divide by zero");
 }
+
+#ifdef HAVE_CLOCK_GETTIME
+#include <time.h>
+# if defined(CLOCK_THREAD_CPUTIME_ID) && defined(CLOCK_TAI)
+struct gcry_timedwait
+{
+  clockid_t id;
+  struct timespec ts;
+};
+
+typedef struct gcry_timedwait *gcry_timedwait_t;
+
+gcry_err_code_t
+_gcry_timedwait_init (gcry_timedwait_t tw, unsigned int flags)
+{
+  /* Possibly, it would be good to be able to select the wall clock.
+   * For now, it's CPU time by the thread.  */
+  if (flags != 0)
+    return GPG_ERR_INV_ARG;
+
+  tw->id = CLOCK_THREAD_CPUTIME_ID;
+  if (clock_gettime (tw->id, &tw->ts) < 0)
+    return gpg_err_code_from_syserror ();
+
+  return 0;
+}
+
+gcry_err_code_t
+_gcry_timedwait_finish (gcry_timedwait_t tw, struct timespec ts_r)
+{
+  struct timespec ts;
+  u32 negative;
+
+  if (clock_gettime (tw->id, &ts) < 0)
+    return gpg_err_code_from_syserror ();
+
+  ts.tv_sec -= tw->ts.tv_sec;
+  ts.tv_nsec -= tw->ts.tv_nsec;
+  negative = ((u32)ts.tv_nsec) >> 31;
+  ts.tv_sec -= negative;
+  ts.tv_nsec += (1000000000 * negative);
+
+  ts_r.tv_sec -= ts.tv_sec;
+  ts_r.tv_nsec -= ts.tv_nsec;
+  negative = ((u32)ts_r.tv_nsec) >> 31;
+  ts_r.tv_sec -= negative;
+  ts_r.tv_nsec += (1000000000 * negative);
+
+  if (ts_r.tv_sec < 0)
+    return GPG_ERR_TIME_CONFLICT;
+
+  if (clock_nanosleep (CLOCK_TAI, 0, &ts_r, &ts_r))
+    return gpg_err_code_from_syserror ();
+
+  return 0;
+}
+# endif
+#endif

--- gnupg-2.4.5/tests/asschk.c	2023-04-04 02:28:39.000000000 -0600
+++ gnupg-2.4.5-c23/tests/asschk.c	2024-04-19 21:21:36.460724329 -0600
@@ -656,13 +656,13 @@
 static int
 eval_boolean (const char *cond)
 {
-  int true = 1;
+  int tr = 1;