diff --git a/cmd/convert.go b/cmd/convert.go
index b6ed91c3..6819a767 100644
--- a/cmd/convert.go
+++ b/cmd/convert.go
@@ -33,6 +33,7 @@ var convertCmd = &cobra.Command{
 	Run: func(cmd *cobra.Command, args []string) {
 
 		t := viper.GetString("type")
+		c := viper.GetInt("concurrency")
 
 		if len(args) != 2 {
 			log.Fatalln("Incorrect number of arguments")
@@ -45,9 +46,9 @@ var convertCmd = &cobra.Command{
 		var builder tree.Parser
 		switch t {
 		case "gentoo":
-			builder = gentoo.NewGentooBuilder(&gentoo.SimpleEbuildParser{})
+			builder = gentoo.NewGentooBuilder(&gentoo.SimpleEbuildParser{}, c)
 		default: // dup
-			builder = gentoo.NewGentooBuilder(&gentoo.SimpleEbuildParser{})
+			builder = gentoo.NewGentooBuilder(&gentoo.SimpleEbuildParser{}, c)
 		}
 
 		packageTree, err := builder.Generate(input)
@@ -74,6 +75,7 @@ var convertCmd = &cobra.Command{
 func init() {
 	convertCmd.Flags().String("type", "gentoo", "source type")
 	viper.BindPFlag("type", convertCmd.Flags().Lookup("type"))
-
+	convertCmd.Flags().Int("concurrency", 30, "Concurrenct")
+	viper.BindPFlag("concurrency", convertCmd.Flags().Lookup("concurrency"))
 	RootCmd.AddCommand(convertCmd)
 }
diff --git a/pkg/tree/builder/gentoo/gentoo.go b/pkg/tree/builder/gentoo/gentoo.go
index fb7b3361..87272177 100644
--- a/pkg/tree/builder/gentoo/gentoo.go
+++ b/pkg/tree/builder/gentoo/gentoo.go
@@ -31,11 +31,14 @@ import (
 	pkg "github.com/mudler/luet/pkg/package"
 )
 
-func NewGentooBuilder(e EbuildParser) tree.Parser {
-	return &GentooBuilder{EbuildParser: e}
+func NewGentooBuilder(e EbuildParser, concurrency int) tree.Parser {
+	return &GentooBuilder{EbuildParser: e, Concurrency: concurrency}
 }
 
-type GentooBuilder struct{ EbuildParser EbuildParser }
+type GentooBuilder struct {
+	EbuildParser EbuildParser
+	Concurrency  int
+}
 
 type GentooTree struct {
 	*tree.DefaultTree
@@ -87,13 +90,12 @@ func (gb *GentooBuilder) Generate(dir string) (pkg.Tree, error) {
 	if err != nil {
 		return nil, err
 	}
-	var numWorkers = 10
 	var toScan = make(chan string)
 	tree := &GentooTree{DefaultTree: &tree.DefaultTree{Packages: pkg.NewBoltDatabase(tmpfile.Name())}}
 
 	// the waitgroup will allow us to wait for all the goroutines to finish at the end
 	var wg = new(sync.WaitGroup)
-	for i := 0; i < numWorkers; i++ {
+	for i := 0; i < gb.Concurrency; i++ {
 		wg.Add(1)
 		go gb.worker(i, wg, toScan, tree)
 	}
diff --git a/pkg/tree/builder/gentoo/gentoo_test.go b/pkg/tree/builder/gentoo/gentoo_test.go
index a016ecaf..447695f0 100644
--- a/pkg/tree/builder/gentoo/gentoo_test.go
+++ b/pkg/tree/builder/gentoo/gentoo_test.go
@@ -34,7 +34,7 @@ var _ = Describe("GentooBuilder", func() {
 
 	Context("Simple test", func() {
 		It("parses correctly deps", func() {
-			gb := NewGentooBuilder(&FakeParser{})
+			gb := NewGentooBuilder(&FakeParser{}, 20)
 			tree, err := gb.Generate("../../../../tests/fixtures/overlay")
 			Expect(err).ToNot(HaveOccurred())
 			Expect(len(tree.GetPackageSet().GetPackages())).To(Equal(10))
diff --git a/pkg/tree/builder/gentoo/simpleparser_test.go b/pkg/tree/builder/gentoo/simpleparser_test.go
index 6f94d8ad..39493295 100644
--- a/pkg/tree/builder/gentoo/simpleparser_test.go
+++ b/pkg/tree/builder/gentoo/simpleparser_test.go
@@ -26,7 +26,7 @@ var _ = Describe("GentooBuilder", func() {
 
 	Context("Simple test", func() {
 		It("parses correctly deps", func() {
-			gb := NewGentooBuilder(&SimpleEbuildParser{})
+			gb := NewGentooBuilder(&SimpleEbuildParser{}, 20)
 			tree, err := gb.Generate("../../../../tests/fixtures/overlay")
 			Expect(err).ToNot(HaveOccurred())
 			defer func() {
diff --git a/pkg/tree/recipes_test.go b/pkg/tree/recipes_test.go
index cc5409c0..55272ce3 100644
--- a/pkg/tree/recipes_test.go
+++ b/pkg/tree/recipes_test.go
@@ -29,7 +29,7 @@ var _ = Describe("Recipe", func() {
 			Expect(err).ToNot(HaveOccurred())
 			defer os.RemoveAll(tmpdir) // clean up
 
-			gb := gentoo.NewGentooBuilder(&gentoo.SimpleEbuildParser{})
+			gb := gentoo.NewGentooBuilder(&gentoo.SimpleEbuildParser{}, 20)
 			tree, err := gb.Generate("../../tests/fixtures/overlay")
 			Expect(err).ToNot(HaveOccurred())
 			defer func() {
@@ -51,7 +51,7 @@ var _ = Describe("Recipe", func() {
 			Expect(err).ToNot(HaveOccurred())
 			defer os.RemoveAll(tmpdir) // clean up
 
-			gb := gentoo.NewGentooBuilder(&gentoo.SimpleEbuildParser{})
+			gb := gentoo.NewGentooBuilder(&gentoo.SimpleEbuildParser{}, 20)
 			tree, err := gb.Generate("../../tests/fixtures/overlay")
 			Expect(err).ToNot(HaveOccurred())
 			defer func() {
@@ -88,7 +88,7 @@ var _ = Describe("Recipe", func() {
 			Expect(err).ToNot(HaveOccurred())
 			defer os.RemoveAll(tmpdir) // clean up
 
-			gb := gentoo.NewGentooBuilder(&gentoo.SimpleEbuildParser{})
+			gb := gentoo.NewGentooBuilder(&gentoo.SimpleEbuildParser{}, 20)
 			tree, err := gb.Generate("../../tests/fixtures/overlay")
 			Expect(err).ToNot(HaveOccurred())
 			defer func() {