diff --git a/documentation/RELEASE_NOTES.html b/documentation/RELEASE_NOTES.html
index 15966b814..6247f5dc7 100644
--- a/documentation/RELEASE_NOTES.html
+++ b/documentation/RELEASE_NOTES.html
@@ -15,6 +15,14 @@ EPICS Base 3.15.0.x releases are not intended for use in production systems.</p>
 <h2 align="center">Changes between 3.15.0.1 and 3.15.0.2</h2>
 <!-- Insert new items immediately below here ... -->
 
+<h3>NTP Time Provider adjusts to OS tick rate changes</h3>
+
+<p>Dirk Zimoch provided code that allows the NTP Time provider (used on VxWorks
+and RTEMS only) to adapt to changes in the OS clock tick rate after the provider
+has been initialized. Note that changing the tick rate after iocInit() is not
+advisable, and that other software might still misbehave if initialized before
+an OS tick rate change.</p>
+
 <h3>Added newEpicsMutex macro</h3>
 
 <p>Internal C++ uses of <tt>new epicsMutex()</tt> have been replaced with a new
diff --git a/src/libCom/osi/osiNTPTime.c b/src/libCom/osi/osiNTPTime.c
index d085cca31..909e6f121 100644
--- a/src/libCom/osi/osiNTPTime.c
+++ b/src/libCom/osi/osiNTPTime.c
@@ -47,8 +47,6 @@ static struct {
     epicsUInt32     syncTick;
     epicsTimeStamp  clockTime;
     epicsUInt32     clockTick;
-    epicsUInt32     nsecsPerTick;
-    epicsUInt32     ticksPerSecond;
     epicsUInt32     ticksToSkip;
     double          tickRate;
 } NTPTimePvt;
@@ -90,8 +88,6 @@ static void NTPTime_InitOnce(void *pprio)
     NTPTimePvt.loopEvent      = epicsEventMustCreate(epicsEventEmpty);
     NTPTimePvt.syncsFailed    = 0;
     NTPTimePvt.lock           = epicsMutexCreate();
-    NTPTimePvt.ticksPerSecond = osdTickRateGet();
-    NTPTimePvt.nsecsPerTick   = NSEC_PER_SEC / NTPTimePvt.ticksPerSecond;
 
     /* Initialize OS-dependent code */
     osdNTPInit();
@@ -100,7 +96,7 @@ static void NTPTime_InitOnce(void *pprio)
     if (!osdNTPGet(&timespecNow)) {
         NTPTimePvt.syncTick = osdTickGet();
         if (timespecNow.tv_sec > POSIX_TIME_AT_EPICS_EPOCH && epicsTimeOK ==
-            epicsTimeFromTimespec(&NTPTimePvt.syncTime, &timespecNow)) {
+                epicsTimeFromTimespec(&NTPTimePvt.syncTime, &timespecNow)) {
             NTPTimePvt.clockTick = NTPTimePvt.syncTick;
             NTPTimePvt.clockTime = NTPTimePvt.syncTime;
             NTPTimePvt.synchronized = 1;
@@ -191,7 +187,7 @@ static void NTPTimeSync(void *dummy)
         if (diff >= 0.0) {
             NTPTimePvt.ticksToSkip = 0;
         } else { /* dont go back in time */
-            NTPTimePvt.ticksToSkip = -diff * NTPTimePvt.ticksPerSecond;
+            NTPTimePvt.ticksToSkip = -diff * osdTickRateGet();
         }
         NTPTimePvt.clockTick = tickNow;
         NTPTimePvt.clockTime = timeNow;
@@ -230,10 +226,12 @@ static int NTPTimeGetCurrent(epicsTimeStamp *pDest)
         }
 
         if (ticksSince) {
-            epicsUInt32 secsSince = ticksSince / NTPTimePvt.ticksPerSecond;
-            ticksSince -= secsSince * NTPTimePvt.ticksPerSecond;
+            epicsUInt32 ticksPerSecond = osdTickRateGet();
+            epicsUInt32 nsecsPerTick = NSEC_PER_SEC / ticksPerSecond;
+            epicsUInt32 secsSince = ticksSince / ticksPerSecond;
 
-            NTPTimePvt.clockTime.nsec += ticksSince * NTPTimePvt.nsecsPerTick;
+            ticksSince -= secsSince * ticksPerSecond;
+            NTPTimePvt.clockTime.nsec += ticksSince * nsecsPerTick;
             if (NTPTimePvt.clockTime.nsec >= NSEC_PER_SEC) {
                 secsSince++;
                 NTPTimePvt.clockTime.nsec -= NSEC_PER_SEC;
@@ -265,14 +263,15 @@ int NTPTime_Report(int level)
         }
         if (level) {
             char lastSync[32];
+
             epicsTimeToStrftime(lastSync, sizeof(lastSync),
                 "%Y-%m-%d %H:%M:%S.%06f", &NTPTimePvt.syncTime);
             printf("Syncronization interval = %.1f seconds\n",
                 NTPTimeSyncInterval);
             printf("Last synchronized at %s\n",
                 lastSync);
-            printf("OS tick rate = %u Hz (nominal)\n",
-                NTPTimePvt.ticksPerSecond);
+            printf("Current OS tick rate = %u Hz\n",
+                osdTickRateGet());
             printf("Measured tick rate = %.3f Hz\n",
                 NTPTimePvt.tickRate);
             osdNTPReport();