diff --git a/graph/bolt/quadstore.go b/graph/bolt/quadstore.go
index 112fd84..bd5fa9e 100644
--- a/graph/bolt/quadstore.go
+++ b/graph/bolt/quadstore.go
@@ -185,7 +185,7 @@ var (
 	metaBucket = []byte("meta")
 )
 
-func (qs *QuadStore) ApplyDeltas(deltas []graph.Delta, ignoreDuplicate bool, ignoreMissing bool) error {
+func (qs *QuadStore) ApplyDeltas(deltas []graph.Delta, ignoreDup, ignoreMiss bool) error {
 	oldSize := qs.size
 	oldHorizon := qs.horizon
 	err := qs.db.Update(func(tx *bolt.Tx) error {
@@ -209,10 +209,10 @@ func (qs *QuadStore) ApplyDeltas(deltas []graph.Delta, ignoreDuplicate bool, ign
 		for _, d := range deltas {
 			err := qs.buildQuadWrite(tx, d.Quad, d.ID.Int(), d.Action == graph.Add)
 			if err != nil {
-				if err == graph.ErrQuadExists && ignoreDuplicate{
+				if err == graph.ErrQuadExists && ignoreDup{
 					continue
 				}
-				if err == graph.ErrQuadNotExist && ignoreMissing{
+				if err == graph.ErrQuadNotExist && ignoreMiss{
 					continue
 				}
 				return err
diff --git a/graph/leveldb/quadstore.go b/graph/leveldb/quadstore.go
index f8fb2d4..b20f62c 100644
--- a/graph/leveldb/quadstore.go
+++ b/graph/leveldb/quadstore.go
@@ -181,7 +181,7 @@ var (
 	cps = [4]quad.Direction{quad.Label, quad.Predicate, quad.Subject, quad.Object}
 )
 
-func (qs *QuadStore) ApplyDeltas(deltas []graph.Delta, ignoreDuplicate bool, ignoreMissing bool) error {
+func (qs *QuadStore) ApplyDeltas(deltas []graph.Delta, ignoreDup, ignoreMiss bool) error {
 	batch := &leveldb.Batch{}
 	resizeMap := make(map[string]int64)
 	sizeChange := int64(0)
@@ -196,10 +196,10 @@ func (qs *QuadStore) ApplyDeltas(deltas []graph.Delta, ignoreDuplicate bool, ign
 		batch.Put(keyFor(d), bytes)
 		err = qs.buildQuadWrite(batch, d.Quad, d.ID.Int(), d.Action == graph.Add)
 		if err != nil {
-			if err == graph.ErrQuadExists && ignoreDuplicate{
+			if err == graph.ErrQuadExists && ignoreDup{
 				continue
 			}
-			if err == graph.ErrQuadNotExist && ignoreMissing{
+			if err == graph.ErrQuadNotExist && ignoreMiss{
 				continue
 			}
 			return err
diff --git a/graph/memstore/quadstore.go b/graph/memstore/quadstore.go
index 5734255..52cb298 100644
--- a/graph/memstore/quadstore.go
+++ b/graph/memstore/quadstore.go
@@ -100,18 +100,18 @@ func newQuadStore() *QuadStore {
 	}
 }
 
-func (qs *QuadStore) ApplyDeltas(deltas []graph.Delta, ignoreDuplicate bool, ignoreMissing bool) error {
+func (qs *QuadStore) ApplyDeltas(deltas []graph.Delta, ignoreDupl, ignoreMiss bool) error {
 	for _, d := range deltas {
 		var err error
 		switch d.Action {
 		case graph.Add:
 			err = qs.AddDelta(d)
-			if err != nil && ignoreDuplicate{
+			if err != nil && ignoreDupl{
 				err = nil
 			}
 		case graph.Delete:
 			err = qs.RemoveDelta(d)
-			if err != nil && ignoreMissing{
+			if err != nil && ignoreMiss{
 				err = nil
 			}
 		default:
diff --git a/graph/mongo/quadstore.go b/graph/mongo/quadstore.go
index f7b4ef9..cb9331a 100644
--- a/graph/mongo/quadstore.go
+++ b/graph/mongo/quadstore.go
@@ -214,7 +214,7 @@ func (qs *QuadStore) updateLog(d graph.Delta) error {
 	return err
 }
 
-func (qs *QuadStore) ApplyDeltas(in []graph.Delta, ignoreDuplicate bool, ignoreMissing bool) error {
+func (qs *QuadStore) ApplyDeltas(in []graph.Delta, ignoreDup, ignoreMiss bool) error {
 	qs.session.SetSafe(nil)
 	ids := make(map[string]int)
 	// Pre-check the existence condition.
@@ -226,7 +226,7 @@ func (qs *QuadStore) ApplyDeltas(in []graph.Delta, ignoreDuplicate bool, ignoreM
 		switch d.Action {
 		case graph.Add:
 			if qs.checkValid(key) {
-				if ignoreDuplicate {
+				if ignoreDup {
 					continue
 				}else{
 					return graph.ErrQuadExists
@@ -234,7 +234,7 @@ func (qs *QuadStore) ApplyDeltas(in []graph.Delta, ignoreDuplicate bool, ignoreM
 			}
 		case graph.Delete:
 			if !qs.checkValid(key) {
-				if ignoreMissing {
+				if ignoreMiss {
 					continue
 				}else{
 					return graph.ErrQuadNotExist
diff --git a/writer/single.go b/writer/single.go
index 96a0ea3..f0f7cb0 100644
--- a/writer/single.go
+++ b/writer/single.go
@@ -33,13 +33,18 @@ type Single struct {
 }
 
 func NewSingleReplication(qs graph.QuadStore, opts graph.Options) (graph.QuadWriter, error) {
-	ignoreMissing, imset := opts.BoolKey("ignore_missing")
-	if !imset {
-		ignoreMissing = *graph.IgnoreMissing
+	var ignoreMissing, ignoreDuplicate bool
+
+	if *graph.IgnoreMissing{
+		ignoreMissing = true
+	}else{
+		ignoreMissing,_ = opts.BoolKey("ignore_missing")
 	}
-	ignoreDuplicate, idset := opts.BoolKey("ignore_duplicate")
-	if !idset {
-		ignoreDuplicate = *graph.IgnoreDup
+
+	if *graph.IgnoreDup{
+		ignoreDuplicate = true
+	}else{
+		ignoreDuplicate,_ = opts.BoolKey("ignore_duplicate")
 	}
 
 	return &Single{