diff --git a/bar.go b/bar.go
index 218988a..f696c6c 100644
--- a/bar.go
+++ b/bar.go
@@ -95,7 +95,7 @@
 	result := make(chan bool)
 	select {
 	case b.operateState <- func(s *bState) { result <- len(s.ewmaDecorators) != 0 }:
-		return b.newProxyReader(r, <-result)
+		return newProxyReader(r, b, <-result)
 	case <-b.done:
 		return nil
 	}
diff --git a/proxyreader.go b/proxyreader.go
index 4bc1ad7..a79a03a 100644
--- a/proxyreader.go
+++ b/proxyreader.go
@@ -52,7 +52,7 @@
 	return n, err
 }
 
-func (b *Bar) newProxyReader(r io.Reader, hasEwma bool) io.ReadCloser {
+func newProxyReader(r io.Reader, b *Bar, hasEwma bool) io.ReadCloser {
 	return toReadCloser(toReader(r, b, hasEwma))
 }