diff --git a/include/haproxy/clock.h b/include/haproxy/clock.h
index 664e53968..3737fc51e 100644
--- a/include/haproxy/clock.h
+++ b/include/haproxy/clock.h
@@ -49,6 +49,7 @@ uint clock_report_idle(void);
 void clock_leaving_poll(int timeout, int interrupted);
 void clock_entering_poll(void);
 void clock_adjust_now_offset(void);
+void clock_set_now_offset(llong ofs);
 
 static inline void clock_update_date(int max_wait, int interrupted)
 {
diff --git a/src/clock.c b/src/clock.c
index 16270aac3..6fba12a1c 100644
--- a/src/clock.c
+++ b/src/clock.c
@@ -364,6 +364,11 @@ void clock_adjust_now_offset(void)
 	HA_ATOMIC_STORE(&now_offset, now_ns - tv_to_ns(&date));
 }
 
+void clock_set_now_offset(llong ofs)
+{
+	HA_ATOMIC_STORE(&now_offset, ofs);
+}
+
 /* must be called once per thread to initialize their thread-local variables.
  * Note that other threads might also be initializing and running in parallel.
  */