diff --git a/local.c b/local.c
index d5762d9..c7b742a 100644
--- a/local.c
+++ b/local.c
@@ -56,6 +56,7 @@ static lcl_AccrueOffsetDriver drv_accrue_offset;
 static lcl_ApplyStepOffsetDriver drv_apply_step_offset;
 static lcl_OffsetCorrectionDriver drv_offset_convert;
 static lcl_SetLeapDriver drv_set_leap;
+static lcl_SetSyncStatusDriver drv_set_sync_status;
 
 /* ================================================== */
 
@@ -557,7 +558,8 @@ lcl_RegisterSystemDrivers(lcl_ReadFrequencyDriver read_freq,
                           lcl_AccrueOffsetDriver accrue_offset,
                           lcl_ApplyStepOffsetDriver apply_step_offset,
                           lcl_OffsetCorrectionDriver offset_convert,
-                          lcl_SetLeapDriver set_leap)
+                          lcl_SetLeapDriver set_leap,
+                          lcl_SetSyncStatusDriver set_sync_status)
 {
   drv_read_freq = read_freq;
   drv_set_freq = set_freq;
@@ -565,6 +567,7 @@ lcl_RegisterSystemDrivers(lcl_ReadFrequencyDriver read_freq,
   drv_apply_step_offset = apply_step_offset;
   drv_offset_convert = offset_convert;
   drv_set_leap = set_leap;
+  drv_set_sync_status = set_sync_status;
 
   current_freq_ppm = (*drv_read_freq)();
 
@@ -632,3 +635,13 @@ LCL_SetTempComp(double comp)
 }
 
 /* ================================================== */
+
+void
+LCL_SetSyncStatus(int synchronised, double est_error, double max_error)
+{
+  if (drv_set_sync_status) {
+    (drv_set_sync_status)(synchronised, est_error, max_error);
+  }
+}
+
+/* ================================================== */
diff --git a/local.h b/local.h
index aff9004..f0c3516 100644
--- a/local.h
+++ b/local.h
@@ -206,4 +206,8 @@ extern void LCL_SetLeap(int leap);
    due to clamping or rounding). */
 extern double LCL_SetTempComp(double comp);
 
+/* Routine to update the synchronisation status in the kernel to allow other
+   applications to know if the system clock is synchronised and error bounds */
+extern void LCL_SetSyncStatus(int synchronised, double est_error, double max_error);
+
 #endif /* GOT_LOCAL_H */
diff --git a/localp.h b/localp.h
index ce92f1c..321985e 100644
--- a/localp.h
+++ b/localp.h
@@ -57,6 +57,9 @@ typedef void (*lcl_OffsetCorrectionDriver)(struct timeval *raw, double *corr, do
 /* System driver to schedule leap second */
 typedef void (*lcl_SetLeapDriver)(int leap);
 
+/* System driver to set the synchronisation status */
+typedef void (*lcl_SetSyncStatusDriver)(int synchronised, double est_error, double max_error);
+
 extern void lcl_InvokeDispersionNotifyHandlers(double dispersion);
 
 extern void
@@ -65,6 +68,7 @@ lcl_RegisterSystemDrivers(lcl_ReadFrequencyDriver read_freq,
                           lcl_AccrueOffsetDriver accrue_offset,
                           lcl_ApplyStepOffsetDriver apply_step_offset,
                           lcl_OffsetCorrectionDriver offset_convert,
-                          lcl_SetLeapDriver set_leap);
+                          lcl_SetLeapDriver set_leap,
+                          lcl_SetSyncStatusDriver set_sync_status);
 
 #endif /* GOT_LOCALP_H */
diff --git a/reference.c b/reference.c
index 0103c38..e6b4bd5 100644
--- a/reference.c
+++ b/reference.c
@@ -928,6 +928,8 @@ REF_SetReference(int stratum,
     LOG(LOGS_WARN, LOGF_Reference, "System clock was stepped by %.6f seconds", -step_offset);
   }
 
+  LCL_SetSyncStatus(are_we_synchronised, offset_sd, offset_sd + root_delay / 2.0 + root_dispersion);
+
   abs_freq_ppm = LCL_ReadAbsoluteFrequency();
 
   write_log(&now,
@@ -1016,6 +1018,8 @@ REF_SetUnsynchronised(void)
   update_leap_status(LEAP_Unsynchronised, 0);
   are_we_synchronised = 0;
 
+  LCL_SetSyncStatus(0, 0.0, 0.0);
+
   write_log(&now,
             "0.0.0.0",
             0,
diff --git a/sys_generic.c b/sys_generic.c
index 2adbbfe..3cdb184 100644
--- a/sys_generic.c
+++ b/sys_generic.c
@@ -275,7 +275,8 @@ SYS_Generic_CompleteFreqDriver(double max_set_freq_ppm, double max_set_freq_dela
                                lcl_ReadFrequencyDriver sys_read_freq,
                                lcl_SetFrequencyDriver sys_set_freq,
                                lcl_ApplyStepOffsetDriver sys_apply_step_offset,
-                               lcl_SetLeapDriver sys_set_leap)
+                               lcl_SetLeapDriver sys_set_leap,
+                               lcl_SetSyncStatusDriver sys_set_sync_status)
 {
   max_freq = max_set_freq_ppm;
   max_freq_change_delay = max_set_freq_delay * (1.0 + max_freq / 1.0e6);
@@ -291,7 +292,7 @@ SYS_Generic_CompleteFreqDriver(double max_set_freq_ppm, double max_set_freq_dela
   lcl_RegisterSystemDrivers(read_frequency, set_frequency,
                             accrue_offset, sys_apply_step_offset ?
                               sys_apply_step_offset : apply_step_offset,
-                            offset_convert, sys_set_leap);
+                            offset_convert, sys_set_leap, NULL);
 
   LCL_AddParameterChangeHandler(handle_step, NULL);
 }
diff --git a/sys_generic.h b/sys_generic.h
index 45c14e2..4532083 100644
--- a/sys_generic.h
+++ b/sys_generic.h
@@ -35,7 +35,8 @@ extern void SYS_Generic_CompleteFreqDriver(double max_set_freq_ppm, double max_s
                                            lcl_ReadFrequencyDriver sys_read_freq,
                                            lcl_SetFrequencyDriver sys_set_freq,
                                            lcl_ApplyStepOffsetDriver sys_apply_step_offset,
-                                           lcl_SetLeapDriver sys_set_leap);
+                                           lcl_SetLeapDriver sys_set_leap,
+                                           lcl_SetSyncStatusDriver sys_set_sync_status);
 
 extern void SYS_Generic_Finalise(void);
 
diff --git a/sys_linux.c b/sys_linux.c
index b342505..d2091b9 100644
--- a/sys_linux.c
+++ b/sys_linux.c
@@ -338,7 +338,7 @@ SYS_Linux_Initialise(void)
                                  1.0 / tick_update_hz,
                                  read_frequency, set_frequency,
                                  have_setoffset ? apply_step_offset : NULL,
-                                 set_leap);
+                                 set_leap, NULL);
 }
 
 /* ================================================== */
diff --git a/sys_netbsd.c b/sys_netbsd.c
index 8c08d4e..c54de3f 100644
--- a/sys_netbsd.c
+++ b/sys_netbsd.c
@@ -307,7 +307,8 @@ SYS_NetBSD_Initialise(void)
   lcl_RegisterSystemDrivers(read_frequency, set_frequency, 
                             accrue_offset, apply_step_offset,
                             get_offset_correction,
-                            NULL /* set_leap */);
+                            NULL /* set_leap */,
+                            NULL /* set_sync_status */);
 
 }
 
diff --git a/sys_solaris.c b/sys_solaris.c
index 0c8dedb..2802a90 100644
--- a/sys_solaris.c
+++ b/sys_solaris.c
@@ -426,7 +426,8 @@ SYS_Solaris_Initialise(void)
   lcl_RegisterSystemDrivers(read_frequency, set_frequency, 
                             accrue_offset, apply_step_offset,
                             get_offset_correction,
-                            NULL /* set_leap */);
+                            NULL /* set_leap */,
+                            NULL /* set_sync_status */);
 
   /* Turn off the kernel switch that keeps the system clock in step
      with the non-volatile clock */
diff --git a/sys_sunos.c b/sys_sunos.c
index d45f58f..9231dca 100644
--- a/sys_sunos.c
+++ b/sys_sunos.c
@@ -379,7 +379,8 @@ SYS_SunOS_Initialise(void)
   lcl_RegisterSystemDrivers(read_frequency, set_frequency, 
                             accrue_offset, apply_step_offset,
                             get_offset_correction,
-                            NULL /* set_leap */);
+                            NULL /* set_leap */,
+                            NULL /* set_sync_status */);
 
   /* Turn off the kernel switch that keeps the system clock in step
      with the non-volatile clock */