diff --git a/pkg/section/parser.go b/pkg/section/parser.go
index 9834dcd..57e5a35 100644
--- a/pkg/section/parser.go
+++ b/pkg/section/parser.go
@@ -22,7 +22,7 @@ func Parse(data []string) (SectionList, error) {
 		if s == "default" {
 			list = append(list, Default{})
 		} else if s == "standard" {
-			list = append(list, Standard{})
+			list = append(list, NewStandard())
 		} else if s == "newline" {
 			list = append(list, NewLine{})
 		} else if strings.HasPrefix(s, "prefix(") && len(d) > 8 {
diff --git a/pkg/section/section.go b/pkg/section/section.go
index cc0a43f..b84ba2c 100644
--- a/pkg/section/section.go
+++ b/pkg/section/section.go
@@ -28,7 +28,7 @@ func (list SectionList) String() []string {
 }
 
 func DefaultSections() SectionList {
-	return SectionList{Standard{}, Default{}}
+	return SectionList{NewStandard(), Default{}}
 }
 
 func DefaultSectionSeparators() SectionList {
diff --git a/pkg/section/standard.go b/pkg/section/standard.go
index 26c7e9d..2b61e9d 100644
--- a/pkg/section/standard.go
+++ b/pkg/section/standard.go
@@ -3,14 +3,30 @@ package section
 import (
 	"github.com/daixiang0/gci/pkg/parse"
 	"github.com/daixiang0/gci/pkg/specificity"
+	"golang.org/x/tools/go/packages"
 )
 
 const StandardType = "standard"
 
-type Standard struct{}
+type Standard struct {
+	standardPackages map[string]struct{}
+}
+
+func NewStandard() Standard {
+	pkgs, err := packages.Load(nil, "std")
+	if err != nil {
+		panic(err)
+	}
+
+	var standardPackages = make(map[string]struct{})
+	for _, p := range pkgs {
+		standardPackages[p.PkgPath] = struct{}{}
+	}
+	return Standard{standardPackages: standardPackages}
+}
 
 func (s Standard) MatchSpecificity(spec *parse.GciImports) specificity.MatchSpecificity {
-	if isStandard(spec.Path) {
+	if _, ok := s.standardPackages[spec.Path]; ok {
 		return specificity.StandardMatch{}
 	}
 	return specificity.MisMatch{}
@@ -23,8 +39,3 @@ func (s Standard) String() string {
 func (s Standard) Type() string {
 	return StandardType
 }
-
-func isStandard(pkg string) bool {
-	_, ok := standardPackages[pkg]
-	return ok
-}
diff --git a/pkg/section/standard_list.go b/pkg/section/standard_list.go
deleted file mode 100644
index 62decfe..0000000
--- a/pkg/section/standard_list.go
+++ /dev/null
@@ -1,160 +0,0 @@
-package section
-
-// Code generated based on go1.19.2. DO NOT EDIT.
-
-var standardPackages = map[string]struct{}{
-	"archive/tar":          {},
-	"archive/zip":          {},
-	"bufio":                {},
-	"bytes":                {},
-	"compress/bzip2":       {},
-	"compress/flate":       {},
-	"compress/gzip":        {},
-	"compress/lzw":         {},
-	"compress/zlib":        {},
-	"container/heap":       {},
-	"container/list":       {},
-	"container/ring":       {},
-	"context":              {},
-	"crypto":               {},
-	"crypto/aes":           {},
-	"crypto/cipher":        {},
-	"crypto/des":           {},
-	"crypto/dsa":           {},
-	"crypto/ecdsa":         {},
-	"crypto/ed25519":       {},
-	"crypto/elliptic":      {},
-	"crypto/hmac":          {},
-	"crypto/md5":           {},
-	"crypto/rand":          {},
-	"crypto/rc4":           {},
-	"crypto/rsa":           {},
-	"crypto/sha1":          {},
-	"crypto/sha256":        {},
-	"crypto/sha512":        {},
-	"crypto/subtle":        {},
-	"crypto/tls":           {},
-	"crypto/x509":          {},
-	"crypto/x509/pkix":     {},
-	"database/sql":         {},
-	"database/sql/driver":  {},
-	"debug/buildinfo":      {},
-	"debug/dwarf":          {},
-	"debug/elf":            {},
-	"debug/gosym":          {},
-	"debug/macho":          {},
-	"debug/pe":             {},
-	"debug/plan9obj":       {},
-	"embed":                {},
-	"encoding":             {},
-	"encoding/ascii85":     {},
-	"encoding/asn1":        {},
-	"encoding/base32":      {},
-	"encoding/base64":      {},
-	"encoding/binary":      {},
-	"encoding/csv":         {},
-	"encoding/gob":         {},
-	"encoding/hex":         {},
-	"encoding/json":        {},
-	"encoding/pem":         {},
-	"encoding/xml":         {},
-	"errors":               {},
-	"expvar":               {},
-	"flag":                 {},
-	"fmt":                  {},
-	"go/ast":               {},
-	"go/build":             {},
-	"go/build/constraint":  {},
-	"go/constant":          {},
-	"go/doc":               {},
-	"go/doc/comment":       {},
-	"go/format":            {},
-	"go/importer":          {},
-	"go/parser":            {},
-	"go/printer":           {},
-	"go/scanner":           {},
-	"go/token":             {},
-	"go/types":             {},
-	"hash":                 {},
-	"hash/adler32":         {},
-	"hash/crc32":           {},
-	"hash/crc64":           {},
-	"hash/fnv":             {},
-	"hash/maphash":         {},
-	"html":                 {},
-	"html/template":        {},
-	"image":                {},
-	"image/color":          {},
-	"image/color/palette":  {},
-	"image/draw":           {},
-	"image/gif":            {},
-	"image/jpeg":           {},
-	"image/png":            {},
-	"index/suffixarray":    {},
-	"io":                   {},
-	"io/fs":                {},
-	"io/ioutil":            {},
-	"log":                  {},
-	"log/syslog":           {},
-	"math":                 {},
-	"math/big":             {},
-	"math/bits":            {},
-	"math/cmplx":           {},
-	"math/rand":            {},
-	"mime":                 {},
-	"mime/multipart":       {},
-	"mime/quotedprintable": {},
-	"net":                  {},
-	"net/http":             {},
-	"net/http/cgi":         {},
-	"net/http/cookiejar":   {},
-	"net/http/fcgi":        {},
-	"net/http/httptest":    {},
-	"net/http/httptrace":   {},
-	"net/http/httputil":    {},
-	"net/http/pprof":       {},
-	"net/mail":             {},
-	"net/netip":            {},
-	"net/rpc":              {},
-	"net/rpc/jsonrpc":      {},
-	"net/smtp":             {},
-	"net/textproto":        {},
-	"net/url":              {},
-	"os":                   {},
-	"os/exec":              {},
-	"os/signal":            {},
-	"os/user":              {},
-	"path":                 {},
-	"path/filepath":        {},
-	"plugin":               {},
-	"reflect":              {},
-	"regexp":               {},
-	"regexp/syntax":        {},
-	"runtime":              {},
-	"runtime/cgo":          {},
-	"runtime/debug":        {},
-	"runtime/metrics":      {},
-	"runtime/pprof":        {},
-	"runtime/race":         {},
-	"runtime/trace":        {},
-	"sort":                 {},
-	"strconv":              {},
-	"strings":              {},
-	"sync":                 {},
-	"sync/atomic":          {},
-	"syscall":              {},
-	"testing":              {},
-	"testing/fstest":       {},
-	"testing/iotest":       {},
-	"testing/quick":        {},
-	"text/scanner":         {},
-	"text/tabwriter":       {},
-	"text/template":        {},
-	"text/template/parse":  {},
-	"time":                 {},
-	"time/tzdata":          {},
-	"unicode":              {},
-	"unicode/utf16":        {},
-	"unicode/utf8":         {},
-	"unsafe":               {},
-}
diff --git a/pkg/section/standard_test.go b/pkg/section/standard_test.go
index 2209402..5627f36 100644
--- a/pkg/section/standard_test.go
+++ b/pkg/section/standard_test.go
@@ -8,13 +8,13 @@ import (
 
 func TestStandardPackageSpecificity(t *testing.T) {
 	testCases := []specificityTestData{
-		{"context", Standard{}, specificity.StandardMatch{}},
-		{"contexts", Standard{}, specificity.MisMatch{}},
-		{"crypto", Standard{}, specificity.StandardMatch{}},
-		{"crypto1", Standard{}, specificity.MisMatch{}},
-		{"crypto/ae", Standard{}, specificity.MisMatch{}},
-		{"crypto/aes", Standard{}, specificity.StandardMatch{}},
-		{"crypto/aes2", Standard{}, specificity.MisMatch{}},
+		{"context", NewStandard(), specificity.StandardMatch{}},
+		{"contexts", NewStandard(), specificity.MisMatch{}},
+		{"crypto", NewStandard(), specificity.StandardMatch{}},
+		{"crypto1", NewStandard(), specificity.MisMatch{}},
+		{"crypto/ae", NewStandard(), specificity.MisMatch{}},
+		{"crypto/aes", NewStandard(), specificity.StandardMatch{}},
+		{"crypto/aes2", NewStandard(), specificity.MisMatch{}},
 	}
 	testSpecificity(t, testCases)
 }