diff --git a/bar.go b/bar.go
index a643df3..ad81d38 100644
--- a/bar.go
+++ b/bar.go
@@ -4,6 +4,7 @@
 	"bytes"
 	"fmt"
 	"io"
+	"io/ioutil"
 	"strings"
 	"sync"
 	"time"
@@ -143,9 +144,16 @@
 	}
 }
 
-// ProxyReader allows progress tracking against provided io.Reader.
+// ProxyReader wraps r with metrics required for progress tracking.
 func (b *Bar) ProxyReader(r io.Reader) io.Reader {
-	return &proxyReader{r, b}
+	if r == nil {
+		panic("expect io.Reader, got nil")
+	}
+	rc, ok := r.(io.ReadCloser)
+	if !ok {
+		rc = ioutil.NopCloser(r)
+	}
+	return &proxyReader{rc, b, time.Now()}
 }
 
 // ID returs id of the bar.
diff --git a/proxyreader.go b/proxyreader.go
index 2bd30f6..d2692cc 100644
--- a/proxyreader.go
+++ b/proxyreader.go
@@ -7,22 +7,16 @@
 
 // proxyReader is io.Reader wrapper, for proxy read bytes
 type proxyReader struct {
-	r io.Reader
-	b *Bar
+	io.ReadCloser
+	bar *Bar
+	iT  time.Time
 }
 
-func (s *proxyReader) Read(p []byte) (n int, err error) {
-	start := time.Now()
-	n, err = s.r.Read(p)
+func (pr *proxyReader) Read(p []byte) (n int, err error) {
+	n, err = pr.ReadCloser.Read(p)
 	if n > 0 {
-		s.b.IncrBy(n, time.Since(start))
+		pr.bar.IncrBy(n, time.Since(pr.iT))
+		pr.iT = time.Now()
 	}
 	return
 }
-
-func (s *proxyReader) Close() error {
-	if closer, ok := s.r.(io.Closer); ok {
-		return closer.Close()
-	}
-	return nil
-}