diff --git a/utils.go b/utils.go
index 9115f5c..b4b4692 100644
--- a/utils.go
+++ b/utils.go
@@ -726,6 +726,8 @@ func setupMakepkg(march string) error {
 		makepkgStr = strings.ReplaceAll(makepkgStr, " check ", " !check ")
 	}
 	makepkgStr = strings.ReplaceAll(makepkgStr, " color ", " !color ")
+	// set Go optimization flag
+	makepkgStr = strings.ReplaceAll(makepkgStr, "LDFLAGS=", "GOAMD64="+march[len(march)-2:]+\nLDFLAGS=")
 	// Add align-functions=32, see https://github.com/InBetweenNames/gentooLTO/issues/164 for more
 	makepkgStr = strings.ReplaceAll(makepkgStr, "-O2", "-O3 -falign-functions=32 -mpclmul -fdevirtualize-at-ltrans")
 	makepkgStr = strings.ReplaceAll(makepkgStr, "#MAKEFLAGS=\"-j2\"", "MAKEFLAGS=\"-j"+strconv.Itoa(conf.Build.Makej)+"\"")