diff --git a/roaring/roaring.go b/roaring/roaring.go
index 035f17ac7..2fe76e8ef 100644
--- a/roaring/roaring.go
+++ b/roaring/roaring.go
@@ -233,15 +233,15 @@ func (b *Bitmap) Count() (n uint64) {
 }
 
 // Size returns the number of bytes required for the bitmap.
-func (b *Bitmap) Size() (numbytes int) {
-
+func (b *Bitmap) Size() int {
+	numbytes := 0
 	citer, _ := b.Containers.Iterator(0)
 	for citer.Next() {
 		_, c := citer.Value()
 		numbytes += c.size()
 
 	}
-	return
+	return numbytes
 }
 
 // CountRange returns the number of bits set between [start, end).