diff --git a/bucket.go b/bucket.go
index 2b0e340..2630800 100644
--- a/bucket.go
+++ b/bucket.go
@@ -645,7 +645,7 @@ func (b *Bucket) free() {
 // dereference removes all references to the old mmap.
 func (b *Bucket) dereference() {
 	if b.rootNode != nil {
-		b.rootNode.dereference()
+		b.rootNode.root().dereference()
 	}
 
 	for _, child := range b.buckets {