diff --git a/cmd/build.go b/cmd/build.go
index d5b882e0..b7301d3b 100644
--- a/cmd/build.go
+++ b/cmd/build.go
@@ -15,11 +15,12 @@
 package cmd
 
 import (
+	"fmt"
 	"io/ioutil"
 	"os"
-	"regexp"
 	"runtime"
 
+	_gentoo "github.com/Sabayon/pkgs-checker/pkg/gentoo"
 	"github.com/mudler/luet/pkg/compiler"
 	"github.com/mudler/luet/pkg/compiler/backend"
 	. "github.com/mudler/luet/pkg/logger"
@@ -95,15 +96,18 @@ var buildCmd = &cobra.Command{
 		luetCompiler.SetCompressionType(compiler.CompressionImplementation(compressionType))
 		if !all {
 			for _, a := range args {
-				decodepackage, err := regexp.Compile(`^([<>]?\~?=?)((([^\/]+)\/)?(?U)(\S+))(-(\d+(\.\d+)*[a-z]?(_(alpha|beta|pre|rc|p)\d*)*(-r\d+)?))?$`)
+				gp, err := _gentoo.ParsePackageStr(a)
 				if err != nil {
-					Fatal("Error: " + err.Error())
+					Fatal("Invalid package string ", a, ": ", err.Error())
 				}
-				packageInfo := decodepackage.FindAllStringSubmatch(a, -1)
-				category := packageInfo[0][4]
-				name := packageInfo[0][5]
-				version := packageInfo[0][1] + packageInfo[0][7]
-				spec, err := luetCompiler.FromPackage(&pkg.DefaultPackage{Name: name, Category: category, Version: version})
+
+				pack := &pkg.DefaultPackage{
+					Name:     gp.Name,
+					Version:  fmt.Sprintf("%s%s", gp.Version, gp.VersionSuffix),
+					Category: gp.Category,
+					Uri:      make([]string, 0),
+				}
+				spec, err := luetCompiler.FromPackage(pack)
 				if err != nil {
 					Fatal("Error: " + err.Error())
 				}