diff --git a/src/runtime/time.go b/src/runtime/time.go
index 75b66f8492..83d93c5686 100644
--- a/src/runtime/time.go
+++ b/src/runtime/time.go
@@ -23,6 +23,8 @@ type timer struct {
 	// Timer wakes up at when, and then at when+period, ... (period > 0 only)
 	// each time calling f(arg, now) in the timer goroutine, so f must be
 	// a well-behaved function and not block.
+	//
+	// when must be positive on an active timer.
 	when   int64
 	period int64
 	f      func(interface{}, uintptr)
diff --git a/src/time/internal_test.go b/src/time/internal_test.go
index 35ce69b228..e70b6f34de 100644
--- a/src/time/internal_test.go
+++ b/src/time/internal_test.go
@@ -53,18 +53,8 @@ func CheckRuntimeTimerOverflow() {
 	t := NewTimer(1)
 
 	defer func() {
-		// Subsequent tests won't work correctly if we don't stop the
-		// overflow timer and kick the timer proc back into service.
-		//
-		// The timer proc is now sleeping and can only be awoken by
-		// adding a timer to the *beginning* of the heap. We can't
-		// wake it up by calling NewTimer since other tests may have
-		// left timers running that should have expired before ours.
-		// Instead we zero the overflow timer duration and start it
-		// once more.
 		stopTimer(r)
 		t.Stop()
-		resetTimer(r, 0)
 	}()
 
 	// If the test fails, we will hang here until the timeout in the