diff --git a/pkg/obialign/fastlcs.go b/pkg/obialign/fastlcs.go
index 98c6c0f..e9d41b8 100644
--- a/pkg/obialign/fastlcs.go
+++ b/pkg/obialign/fastlcs.go
@@ -69,6 +69,10 @@ func FastLCSScore(seqA, seqB *obiseq.BioSequence, maxError int, buffer *[]uint64
 		lA, lB = lB, lA
 	}
 
+	if maxError == -1 {
+		maxError = lA*2
+	}
+
 	delta := lA - lB
 
 	// The difference of length is larger the maximum allowed errors
diff --git a/pkg/obialign/fulllcs.go b/pkg/obialign/fulllcs.go
deleted file mode 100644
index 2d2189e..0000000
--- a/pkg/obialign/fulllcs.go
+++ /dev/null
@@ -1,118 +0,0 @@
-package obialign
-
-import (
-	"log"
-
-	"git.metabarcoding.org/lecasofts/go/obitools/pkg/obiseq"
-)
-
-type FullLCSMatrix struct {
-	matrix []int16 // Score matrix
-	lenght []int16 // Alignment length matrix
-	ll     int     // Length of the longest sequence
-	l      int     // Length of the shortest sequence
-}
-
-func NewFullLCSMatrix(matrix *FullLCSMatrix, L, l int) *FullLCSMatrix {
-	if matrix == nil {
-		matrix = &FullLCSMatrix{}
-	}
-
-	if l > L {
-		log.Panicf("L (%d) must be greater or equal to l (%d)", L, l)
-	}
-
-	needed := (L) * (l)
-
-	if needed > matrix.Cap() {
-		matrix.matrix = make([]int16, needed)
-		matrix.lenght = make([]int16, needed)
-	}
-
-	matrix.matrix = matrix.matrix[:needed]
-	matrix.lenght = matrix.lenght[:needed]
-
-	matrix.ll = L
-	matrix.l = l
-
-	return matrix
-}
-
-func (matrix *FullLCSMatrix) Cap() int {
-	return cap(matrix.matrix)
-}
-
-func (matrix *FullLCSMatrix) Length() int {
-	return len(matrix.matrix)
-}
-
-func (matrix *FullLCSMatrix) Get(i, j int) (int16, int16) {
-	if i == 0 {
-		return 0, int16(j)
-	}
-	if j == 0 {
-		return 0, int16(i)
-	}
-
-	pos := (i-1)*matrix.ll + j - 1
-	return matrix.matrix[pos], matrix.lenght[pos]
-}
-
-func (matrix *FullLCSMatrix) Set(i, j int, score, length int16) {
-	if i > 0 && j > 0 {
-		pos := (i-1)*matrix.ll + j - 1
-		matrix.matrix[pos] = score
-		matrix.lenght[pos] = length
-	}
-}
-
-// Computes the LCS between two DNA sequences and the length of the
-// corresponding alignment
-func FullLCSScore(seqA, seqB *obiseq.BioSequence,
-	matrix *FullLCSMatrix) (int, int) {
-
-	if seqA.Length() == 0 {
-		log.Fatal("Sequence A has a length of 0")
-	}
-
-	if seqB.Length() == 0 {
-		log.Fatal("Sequence B has a length of 0")
-	}
-	// swapped := false
-
-	if seqA.Length() < seqB.Length() {
-		seqA, seqB = seqB, seqA
-		// swapped = true
-	}
-
-	la := seqA.Length()
-	lb := seqB.Length()
-	sa := seqA.Sequence()
-	sb := seqB.Sequence()
-
-	matrix = NewFullLCSMatrix(matrix, la, lb)
-
-	for i := 1; i <= matrix.l; i++ {
-		for j := 1; j <= matrix.ll; j++ {
-			sd, ld := matrix.Get(i-1, j-1)
-
-			if sb[i-1] == sa[j-1] {
-				sd++
-			}
-			sup, lup := matrix.Get(i-1, j)
-			sleft, lleft := matrix.Get(i, j-1)
-			switch {
-			case sd >= sup && sd >= sleft:
-				matrix.Set(i, j, sd, ld+1)
-			case sup >= sleft && sup >= sd:
-				matrix.Set(i, j, sup, lup+1)
-			default:
-				matrix.Set(i, j, sleft, lleft+1)
-			}
-		}
-	}
-
-	s, l := matrix.Get(lb, la)
-
-	return int(s), int(l)
-}
diff --git a/pkg/obitools/obirefidx/obirefidx.go b/pkg/obitools/obirefidx/obirefidx.go
index 54e67bf..7c0006f 100644
--- a/pkg/obitools/obirefidx/obirefidx.go
+++ b/pkg/obitools/obirefidx/obirefidx.go
@@ -28,11 +28,16 @@ func IndexSequence(seqidx int,
 	var matrix []uint64
 
 	score := make([]int, len(references))
+	// t := 0
+	// r := 0
+	// w := 0
 	for i, ref := range references {
-		lcs, alilength := obialign.FastLCSScore(sequence, ref, goutils.MaxInt(sequence.Length(), ref.Length())+5, &matrix)
+		lcs, alilength := obialign.FastLCSScore(sequence, ref, -1 , &matrix)
 		score[i] = alilength - lcs
 	}
 
+	// log.Println("Redone : ",r,"/",t,"(",w,")")
+
 	o := goutils.IntOrder(score)
 
 	current_taxid, err := taxo.Taxon(references[o[0]].Taxid())