diff --git a/bar.go b/bar.go
index 9472f5a..db8a350 100644
--- a/bar.go
+++ b/bar.go
@@ -90,7 +90,14 @@
 	if r == nil {
 		panic("expected non nil io.Reader")
 	}
-	return b.newProxyReader(r)
+	result := make(chan bool)
+	select {
+	case b.operateState <- func(s *bState) { result <- s.triggerComplete }:
+		triggerComplete := <-result
+		return b.newProxyReader(r, !triggerComplete)
+	case <-b.done:
+		return nil
+	}
 }
 
 // ID returs id of the bar.
diff --git a/proxyreader.go b/proxyreader.go
index 582a55e..c9a14b0 100644
--- a/proxyreader.go
+++ b/proxyreader.go
@@ -8,13 +8,14 @@
 
 type proxyReader struct {
 	io.ReadCloser
-	bar *Bar
+	bar          *Bar
+	totalUnknown bool
 }
 
 func (x proxyReader) Read(p []byte) (int, error) {
 	n, err := x.ReadCloser.Read(p)
 	x.bar.IncrBy(n)
-	if err == io.EOF {
+	if x.totalUnknown && err == io.EOF {
 		go x.bar.SetTotal(-1, true)
 	}
 	return n, err
@@ -28,7 +29,7 @@
 func (x proxyWriterTo) WriteTo(w io.Writer) (int64, error) {
 	n, err := x.wt.WriteTo(w)
 	x.bar.IncrInt64(n)
-	if err == io.EOF {
+	if x.totalUnknown && err == io.EOF {
 		go x.bar.SetTotal(-1, true)
 	}
 	return n, err
@@ -61,8 +62,8 @@
 	return n, err
 }
 
-func (b *Bar) newProxyReader(r io.Reader) (rc io.ReadCloser) {
-	pr := proxyReader{toReadCloser(r), b}
+func (b *Bar) newProxyReader(r io.Reader, totalUnknown bool) (rc io.ReadCloser) {
+	pr := proxyReader{toReadCloser(r), b, totalUnknown}
 	if wt, ok := r.(io.WriterTo); ok {
 		pw := proxyWriterTo{pr, wt}
 		if b.hasEwma {