diff --git a/roaring/roaring.go b/roaring/roaring.go
index 9343828f5..0e039b970 100644
--- a/roaring/roaring.go
+++ b/roaring/roaring.go
@@ -16,6 +16,7 @@
 package roaring
 
 import (
+	"bytes"
 	"encoding/binary"
 	"errors"
 	"fmt"
@@ -101,6 +102,14 @@ func (b *Bitmap) Add(a ...uint64) (changed bool, err error) {
 
 	return changed, nil
 }
+func (b *Bitmap) String() string {
+	var buffer bytes.Buffer
+	for _, v := range b.Slice() {
+		buffer.WriteString(fmt.Sprintf("%d ", v))
+	}
+	buffer.WriteString("\n")
+	return buffer.String()
+}
 
 func (b *Bitmap) add(v uint64) bool {
 	hb := highbits(v)
@@ -710,9 +719,12 @@ func (b *Bitmap) Check() error {
 func (b *Bitmap) Flip(start, end uint64) *Bitmap {
 	result := NewBitmap()
 	itr := b.Iterator()
-	itr.Seek(start)
 	v, eof := itr.Next()
-	for i := start; i < end; i++ {
+	for v < start && !eof {
+		result.add(v)
+		v, eof = itr.Next()
+	}
+	for i := start; i <= end; i++ {
 		if eof {
 			result.add(i)
 		} else if v == i {
diff --git a/roaring/roaring_test.go b/roaring/roaring_test.go
index eb5f912c6..c1d162551 100644
--- a/roaring/roaring_test.go
+++ b/roaring/roaring_test.go
@@ -203,7 +203,7 @@ func TestBitmap_Xor_BitmapBitmap(t *testing.T) {
 func TestBitmap_Flip_Empty(t *testing.T) {
 	bm := roaring.NewBitmap()
 	results := bm.Flip(0, 10)
-	if n := results.Count(); n != 10 {
+	if n := results.Count(); n != 11 {
 		t.Fatalf("unexpected n: %d", n)
 	}
 	results = results.Flip(0, 10)
@@ -215,13 +215,13 @@ func TestBitmap_Flip_Empty(t *testing.T) {
 // Test Subrange Flip should not affect bits outside of Range
 func TestBitmap_Flip_Array(t *testing.T) {
 	bm := roaring.NewBitmap(0, 1, 2, 3, 4, 8, 16, 32, 64, 128, 256, 512, 1024)
-	results := bm.Flip(0, 5)
-	if n := results.Count(); n != 8 {
-		t.Fatalf("unexpected n: %d", n)
+	results := bm.Flip(0, 4)
+	if !reflect.DeepEqual(results.Slice(), []uint64{8, 16, 32, 64, 128, 256, 512, 1024}) {
+		t.Fatalf("unexpected %s ", results.String())
 	}
-	results = results.Flip(0, 5)
-	if n := results.Count(); n != 13 {
-		t.Fatalf("unexpected n: %d", n)
+	results = results.Flip(0, 4)
+	if !reflect.DeepEqual(results.Slice(), []uint64{0, 1, 2, 3, 4, 8, 16, 32, 64, 128, 256, 512, 1024}) {
+		t.Fatalf("unexpected %s ", results.String())
 	}
 
 }
@@ -232,16 +232,34 @@ func TestBitmap_Flip_Bitmap(t *testing.T) {
 	for i := uint64(0); i < size; i += 2 {
 		bm.Add(i)
 	}
-	results := bm.Flip(0, size)
+	results := bm.Flip(0, size-1)
 	if n := results.Count(); n != size/2 {
 		t.Fatalf("unexpected n: %d", n)
 	}
-	results = results.Flip(0, size) //flipping back should be the same
+	results = results.Flip(0, size-1) //flipping back should be the same
 	if n := results.Count(); n != size/2 {
 		t.Fatalf("unexpected n: %d", n)
 	}
 }
 
+func TestBitmap_Flip_After(t *testing.T) {
+	bm := roaring.NewBitmap(0, 2, 4, 8)
+	results := bm.Flip(9, 10)
+
+	if !reflect.DeepEqual(results.Slice(), []uint64{0, 2, 4, 8, 9, 10}) {
+		t.Fatalf("unexpected %s ", results.String())
+	}
+	results = results.Flip(0, 1)
+	if !reflect.DeepEqual(results.Slice(), []uint64{1, 2, 4, 8, 9, 10}) {
+		t.Fatalf("unexpected %s ", results.String())
+	}
+	results = results.Flip(4, 8)
+	if !reflect.DeepEqual(results.Slice(), []uint64{1, 2, 5, 6, 7, 9, 10}) {
+		t.Fatalf("unexpected %s ", results.String())
+	}
+
+}
+
 // Ensure bitmap can return the number of intersecting bits in two bitmaps.
 func TestBitmap_IntersectionCount_ArrayArray(t *testing.T) {
 	bm0 := roaring.NewBitmap(0, 1000001, 1000002, 1000003)