diff --git a/wgengine/monitor/monitor.go b/wgengine/monitor/monitor.go
index f5e3f64d6..d2ddfb8c3 100644
--- a/wgengine/monitor/monitor.go
+++ b/wgengine/monitor/monitor.go
@@ -185,13 +185,7 @@ func (m *Mon) Start() {
 	}
 	m.started = true
 
-	switch runtime.GOOS {
-	case "ios", "android":
-		// For battery reasons, and because these platforms
-		// don't really sleep in the same way, don't poll
-		// for the wall time to detect for wake-for-sleep
-		// walltime jumps.
-	default:
+	if shouldMonitorTimeJump {
 		m.wallTimer = time.AfterFunc(pollWallTimeInterval, m.pollWallTime)
 	}
 
@@ -304,16 +298,9 @@ func (m *Mon) debounce() {
 		} else {
 			m.mu.Lock()
 
-			// See if we have a queued or new time jump signal.
-			m.checkWallTimeAdvanceLocked()
-			timeJumped := m.timeJumped
-			if timeJumped {
-				m.logf("time jumped (probably wake from sleep); synthesizing major change event")
-			}
-
 			oldState := m.ifState
-			ifChanged := !curState.EqualFiltered(oldState, interfaces.UseInterestingInterfaces, interfaces.UseInterestingIPs)
-			if ifChanged {
+			changed := !curState.EqualFiltered(oldState, interfaces.UseInterestingInterfaces, interfaces.UseInterestingIPs)
+			if changed {
 				m.gwValid = false
 				m.ifState = curState
 
@@ -322,9 +309,14 @@ func (m *Mon) debounce() {
 						jsonSummary(oldState), jsonSummary(curState))
 				}
 			}
-			changed := ifChanged || timeJumped
-			if changed {
-				m.timeJumped = false
+			// See if we have a queued or new time jump signal.
+			if shouldMonitorTimeJump && m.checkWallTimeAdvanceLocked() {
+				m.resetTimeJumpedLocked()
+				if !changed {
+					// Only log if it wasn't an interesting change.
+					m.logf("time jumped (probably wake from sleep); synthesizing major change event")
+					changed = true
+				}
 			}
 			for _, cb := range m.cbs {
 				go cb(changed, m.ifState)
@@ -360,22 +352,37 @@ func (m *Mon) pollWallTime() {
 	if m.closed {
 		return
 	}
-	m.checkWallTimeAdvanceLocked()
-	if m.timeJumped {
+	if m.checkWallTimeAdvanceLocked() {
 		m.InjectEvent()
 	}
 	m.wallTimer.Reset(pollWallTimeInterval)
 }
 
-// checkWallTimeAdvanceLocked updates m.timeJumped, if wall time jumped
-// more than 150% of pollWallTimeInterval, indicating we probably just
-// came out of sleep.
-func (m *Mon) checkWallTimeAdvanceLocked() {
+// shouldMonitorTimeJump is whether we keep a regular periodic timer running in
+// the background watching for jumps in wall time.
+//
+// We don't do this on mobile platforms for battery reasons, and because these
+// platforms don't really sleep in the same way.
+const shouldMonitorTimeJump = runtime.GOOS != "android" && runtime.GOOS != "ios"
+
+// checkWallTimeAdvanceLocked reports whether wall time jumped more than 150% of
+// pollWallTimeInterval, indicating we probably just came out of sleep. Once a
+// time jump is detected it must be reset by calling resetTimeJumpedLocked.
+func (m *Mon) checkWallTimeAdvanceLocked() bool {
+	if !shouldMonitorTimeJump {
+		panic("unreachable") // if callers are correct
+	}
 	now := wallTime()
 	if now.Sub(m.lastWall) > pollWallTimeInterval*3/2 {
-		m.timeJumped = true
+		m.timeJumped = true // it is reset by debounce.
 	}
 	m.lastWall = now
+	return m.timeJumped
+}
+
+// resetTimeJumpedLocked consumes the signal set by checkWallTimeAdvanceLocked.
+func (m *Mon) resetTimeJumpedLocked() {
+	m.timeJumped = false
 }
 
 type ipRuleDeletedMessage struct {