diff --git a/roaring/containers_skiplist.go b/roaring/containers_skiplist.go
deleted file mode 100644
index 07d6dc870..000000000
--- a/roaring/containers_skiplist.go
+++ /dev/null
@@ -1,96 +0,0 @@
-package roaring
-
-import "github.com/pilosa/fast-skiplist"
-
-func NewSkipListContainers() *SkipListContainers {
-	return &SkipListContainers{
-		list: skiplist.New(),
-	}
-}
-
-type SkipListContainers struct {
-	list *skiplist.SkipList
-}
-
-func (slc *SkipListContainers) Get(key uint64) *container {
-	var c *container
-	el := slc.list.Get(key)
-	if el != nil {
-		c = el.Value().(*container)
-	}
-	return c
-}
-
-func (slc *SkipListContainers) Put(key uint64, c *container) {
-	slc.list.Set(key, c)
-}
-
-func (slc *SkipListContainers) PutContainerValues(key uint64, containerType byte, n int, mapped bool) {
-}
-
-func (slc *SkipListContainers) Remove(key uint64) {
-	slc.list.Remove(key)
-}
-
-func (slc *SkipListContainers) GetOrCreate(key uint64) *container {
-	el := slc.list.Get(key)
-	if el == nil {
-		return slc.list.Set(key, newContainer()).Value().(*container)
-	}
-	return el.Value().(*container)
-}
-
-func (slc *SkipListContainers) Clone() Containers {
-	nslc := NewSkipListContainers()
-	for c := slc.list.Front(); c != nil; c = c.Next() {
-		nslc.list.Set(c.Key(), c.Value().(*container).clone())
-	}
-	return nslc
-}
-
-func (slc *SkipListContainers) Last() (key uint64, c *container) {
-	if slc.list.Length() == 0 {
-		return 0, nil
-	}
-	el := slc.list.Last()
-	return el.Key(), el.Value().(*container)
-}
-
-func (slc *SkipListContainers) Size() int {
-	return slc.list.Length()
-}
-
-func (slc *SkipListContainers) Iterator(key uint64) (citer Contiterator, found bool) {
-	el := slc.list.GetNext(key)
-	if el != nil && el.Key() == key {
-		found = true
-	}
-
-	return &SLCIterator{
-		el: el,
-	}, found
-}
-
-type SLCIterator struct {
-	started bool
-	el      *skiplist.Element
-}
-
-func (i *SLCIterator) Next() bool {
-	if i.el == nil {
-		return false
-	}
-	if !i.started {
-		i.started = true
-		return true
-	}
-	i.el = i.el.Next()
-	return i.el != nil
-}
-
-func (i *SLCIterator) Value() (uint64, *container) {
-	if !i.started || i.el == nil {
-		return 0, nil
-	}
-	return i.el.Key(), i.el.Value().(*container)
-}
diff --git a/roaring/roaring.go b/roaring/roaring.go
index 6feb90166..8ac2b4d4e 100644
--- a/roaring/roaring.go
+++ b/roaring/roaring.go
@@ -166,8 +166,7 @@ func (b *Bitmap) Add(a ...uint64) (changed bool, err error) {
 }
 
 func (b *Bitmap) add(v uint64) bool {
-	hb := highbits(v)
-	cont := b.conts.GetOrCreate(hb)
+	cont := b.conts.GetOrCreate(highbits(v))
 	return cont.add(lowbits(v))
 }