diff --git a/cl/builtin_test.go b/cl/builtin_test.go
index 3f09e167d..ac3e07076 100644
--- a/cl/builtin_test.go
+++ b/cl/builtin_test.go
@@ -39,6 +39,20 @@ func getGoxConf() *gox.Config {
 	return &gox.Config{Fset: fset, Importer: imp}
 }
 
+func TestExt(t *testing.T) {
+	cases := [][2]string{
+		{"t.spx.gox", ".spx"},
+		{"t.spx", ".spx"},
+		{"t.gox", ".gox"},
+		{"t.abc", ".abc"},
+	}
+	for _, c := range cases {
+		if ret := ClassFileExt(c[0]); ret != c[1] {
+			t.Fatal("ClassFileExt:", c[0], "expected:", c[1], "got:", ret)
+		}
+	}
+}
+
 func TestErrMultiStarRecv(t *testing.T) {
 	defer func() {
 		if e := recover(); e == nil {
diff --git a/cl/classfile.go b/cl/classfile.go
index 7c6b5f1c3..91cbb18fc 100644
--- a/cl/classfile.go
+++ b/cl/classfile.go
@@ -24,7 +24,6 @@ import (
 	"strings"
 
 	"github.com/goplus/gop/ast"
-	"github.com/goplus/gop/parser"
 	"github.com/goplus/gop/token"
 	"github.com/goplus/gox"
 )
@@ -61,7 +60,7 @@ func (p *gmxSettings) getScheds(cb *gox.CodeBuilder) []goast.Stmt {
 }
 
 func newGmx(ctx *pkgCtx, pkg *gox.Package, file string, f *ast.File, conf *Config) *gmxSettings {
-	ext := parser.ClassFileExt(file)
+	ext := ClassFileExt(file)
 	gt, ok := conf.LookupClass(ext)
 	if !ok {
 		panic("TODO: class not found")
@@ -177,3 +176,16 @@ func gmxMainFunc(p *gox.Package, ctx *pkgCtx) {
 }
 
 // -----------------------------------------------------------------------------
+
+// ClassFileExt returns the classfile extension
+func ClassFileExt(path string) (ext string) {
+	ext = filepath.Ext(path)
+	if ext == ".gox" {
+		if c := filepath.Ext(path[:len(path)-4]); c != "" {
+			return c
+		}
+	}
+	return
+}
+
+// -----------------------------------------------------------------------------
diff --git a/cl/compile.go b/cl/compile.go
index 25a34f279..830aa5c97 100644
--- a/cl/compile.go
+++ b/cl/compile.go
@@ -28,7 +28,6 @@ import (
 
 	"github.com/goplus/gop/ast"
 	"github.com/goplus/gop/ast/fromgo"
-	"github.com/goplus/gop/parser"
 	"github.com/goplus/gop/token"
 	"github.com/goplus/gox"
 	"github.com/goplus/gox/cpackages"
@@ -710,7 +709,7 @@ func preloadGopFile(p *gox.Package, ctx *blockCtx, file string, f *ast.File, con
 	case f.IsClass:
 		classType = getDefaultClass(file)
 		if parent.gmxSettings != nil {
-			ext := parser.ClassFileExt(file)
+			ext := ClassFileExt(file)
 			o, ok := parent.sprite[ext]
 			if ok {
 				baseTypeName, baseType, spxClass = o.Name(), o.Type(), true
diff --git a/parser/classfile.go b/parser/classfile.go
deleted file mode 100644
index d4a3e3d82..000000000
--- a/parser/classfile.go
+++ /dev/null
@@ -1,32 +0,0 @@
-/*
- * Copyright (c) 2021 The GoPlus Authors (goplus.org). All rights reserved.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package parser
-
-import (
-	"path/filepath"
-)
-
-// ClassFileExt returns the classfile extension
-func ClassFileExt(path string) (ext string) {
-	ext = filepath.Ext(path)
-	if ext == ".gox" {
-		if c := filepath.Ext(path[:len(path)-4]); c != "" {
-			return c
-		}
-	}
-	return
-}
diff --git a/parser/parser_test.go b/parser/parser_test.go
index a387edc41..9a90a7de9 100644
--- a/parser/parser_test.go
+++ b/parser/parser_test.go
@@ -45,20 +45,6 @@ func TestAssert(t *testing.T) {
 	assert(false, "panic msg")
 }
 
-func TestExt(t *testing.T) {
-	cases := [][2]string{
-		{"t.spx.gox", ".spx"},
-		{"t.spx", ".spx"},
-		{"t.gox", ".gox"},
-		{"t.abc", ".abc"},
-	}
-	for _, c := range cases {
-		if ret := ClassFileExt(c[0]); ret != c[1] {
-			t.Fatal("ClassFileExt:", c[0], "expected:", c[1], "got:", ret)
-		}
-	}
-}
-
 func panicMsg(e interface{}) string {
 	switch v := e.(type) {
 	case string: