diff --git a/tagalign.go b/tagalign.go
index 8896a14..1d79b35 100644
--- a/tagalign.go
+++ b/tagalign.go
@@ -4,13 +4,13 @@ import (
 	"cmp"
 	"fmt"
 	"go/ast"
+	"go/token"
 	"reflect"
 	"slices"
 	"strconv"
 	"strings"
 
 	"github.com/fatih/structtag"
-
 	"golang.org/x/tools/go/analysis"
 )
 
@@ -38,6 +38,13 @@ func NewAnalyzer(options ...Option) *analysis.Analyzer {
 
 func Run(pass *analysis.Pass, options ...Option) {
 	for _, f := range pass.Files {
+		filename := getFilename(pass.Fset, f)
+		if !strings.HasSuffix(filename, ".go") {
+			continue
+		}
+
+		println(filename)
+
 		h := &Helper{
 			style: DefaultStyle,
 			align: true,
@@ -378,3 +385,12 @@ func removeField(fields []*ast.Field, index int) []*ast.Field {
 
 	return append(fields[:index], fields[index+1:]...)
 }
+
+func getFilename(fset *token.FileSet, file *ast.File) string {
+	filename := fset.PositionFor(file.Pos(), true).Filename
+	if !strings.HasSuffix(filename, ".go") {
+		return fset.PositionFor(file.Pos(), false).Filename
+	}
+
+	return filename
+}
diff --git a/tagalign_test.go b/tagalign_test.go
index 59afebf..68189cf 100644
--- a/tagalign_test.go
+++ b/tagalign_test.go
@@ -57,6 +57,12 @@ func TestAnalyzer(t *testing.T) {
 	}
 }
 
+func TestAnalyzer_cgo(t *testing.T) {
+	a := NewAnalyzer()
+
+	analysistest.Run(t, analysistest.TestData(), a, "cgo")
+}
+
 func Test_alignFormat(t *testing.T) {
 	format := alignFormat(20)
 	assert.Equal(t, "%-20s", format)
diff --git a/testdata/src/cgo/cgo.go b/testdata/src/cgo/cgo.go
new file mode 100644
index 0000000..a929e26
--- /dev/null
+++ b/testdata/src/cgo/cgo.go
@@ -0,0 +1,43 @@
+package cgo
+
+/*
+ #include <stdio.h>
+ #include <stdlib.h>
+
+ void myprint(char* s) {
+ 	printf("%d\n", s);
+ }
+*/
+import "C"
+
+import (
+	"unsafe"
+)
+
+func _() {
+	cs := C.CString("Hello from stdio\n")
+	C.myprint(cs)
+	C.free(unsafe.Pointer(cs))
+}
+
+type FooBar struct {
+	Foo    int    `json:"foo"        validate:"required"`                    // want `tag is not aligned, should be: json:"foo"`
+	Bar    string `json:"___bar___,omitempty"  validate:"required"`          // want `json:"___bar___,omitempty" validate:"required"`
+	FooFoo int8   `json:"foo_foo"    validate:"required"      yaml:"fooFoo"` // want `tag is not aligned, should be: json:"foo_foo"`
+	BarBar int    `json:"bar_bar"         validate:"required"`               // want `tag is not aligned, should be: json:"bar_bar"`
+	FooBar struct {
+		Foo    int    `json:"foo"    yaml:"foo"     validate:"required"` // want `tag is not aligned, should be: json:"foo"    yaml:"foo"          validate:"required"`
+		Bar222 string `json:"bar222"   validate:"required"  yaml:"bar"`  // want `tag is not aligned, should be: json:"bar222" validate:"required" yaml:"bar"`
+	} `json:"foo_bar" validate:"required"`
+	FooFooFoo struct {
+		BarBarBar struct {
+			BarBarBarBar    string `json:"bar_bar_bar_bar" validate:"required"`                // want `json:"bar_bar_bar_bar"     validate:"required"`
+			BarBarBarFooBar string `json:"bar_bar_bar_foo_bar" yaml:"bar" validate:"required"` // want `tag is not aligned, should be: json:"bar_bar_bar_foo_bar" yaml:"bar"          validate:"required"`
+		} `json:"bar_bar_bar" validate:"required"`
+	}
+	BarFooBarFoo struct{}
+	// test comment
+	// test commnet 2
+	BarFoo    string `json:"bar_foo" validate:"required"` // want `tag is not aligned, should be: json:"bar_foo"     validate:"required"`
+	BarFooBar string `json:"bar_foo_bar" validate:"required"`
+}