diff --git a/chore/_xtool/llcppsigfetch/parse/cvt.go b/chore/_xtool/llcppsigfetch/parse/cvt.go
index ff93aa0f..4340dd4e 100644
--- a/chore/_xtool/llcppsigfetch/parse/cvt.go
+++ b/chore/_xtool/llcppsigfetch/parse/cvt.go
@@ -488,10 +488,15 @@ func (ct *Converter) ProcessBuiltinType(t clang.Type) *ast.BuiltinType {
 		flags |= ast.Long | ast.Double
 	case clang.TypeFloat128:
 		kind = ast.Float128
-	case clang.TypeComplex: // double | float
+	case clang.TypeComplex:
 		kind = ast.Complex
 		complexKind := t.ElementType().Kind
-		println("complex kind:", complexKind) // in unit test, will panic
+		if complexKind == clang.TypeLongDouble {
+			flags |= ast.Long | ast.Double
+		} else if complexKind == clang.TypeDouble {
+			flags |= ast.Double
+		}
+		// float complfex flag is not set
 	default:
 		// like IBM128,NullPtr,Accum
 		kindStr := t.Kind.String()
diff --git a/chore/_xtool/llcppsigfetch/parse/cvt_test/type_test/llgo.expect b/chore/_xtool/llcppsigfetch/parse/cvt_test/type_test/llgo.expect
index 9d5fac9c..4ef2b3c1 100644
--- a/chore/_xtool/llcppsigfetch/parse/cvt_test/type_test/llgo.expect
+++ b/chore/_xtool/llcppsigfetch/parse/cvt_test/type_test/llgo.expect
@@ -22,6 +22,9 @@ Float16:flags:0 kind:9
 Double:flags:16 kind:8
 LongDouble:flags:20 kind:8
 Float128:flags:0 kind:10
+Complex:flags:0 kind:11
+Complex:flags:16 kind:11
+Complex:flags:20 kind:11
 Unknown:flags:0 kind:0
 
 #stderr
diff --git a/chore/_xtool/llcppsigfetch/parse/cvt_test/type_test/type.go b/chore/_xtool/llcppsigfetch/parse/cvt_test/type_test/type.go
index e414e985..c7260d10 100644
--- a/chore/_xtool/llcppsigfetch/parse/cvt_test/type_test/type.go
+++ b/chore/_xtool/llcppsigfetch/parse/cvt_test/type_test/type.go
@@ -2,6 +2,7 @@ package main
 
 import (
 	"fmt"
+	"unsafe"
 
 	"github.com/goplus/llgo/c/clang"
 	"github.com/goplus/llgo/chore/_xtool/llcppsigfetch/parse"
@@ -14,7 +15,7 @@ func main() {
 func TestBuiltinType() {
 	tests := []struct {
 		name     string
-		typ      *clang.Type
+		typ      clang.Type
 		expected ast.BuiltinType
 	}{
 		{"Void", btType(clang.TypeVoid), ast.BuiltinType{Kind: ast.Void}},
@@ -40,13 +41,16 @@ func TestBuiltinType() {
 		{"Double", btType(clang.TypeDouble), ast.BuiltinType{Kind: ast.Float, Flags: ast.Double}},
 		{"LongDouble", btType(clang.TypeLongDouble), ast.BuiltinType{Kind: ast.Float, Flags: ast.Long | ast.Double}},
 		{"Float128", btType(clang.TypeFloat128), ast.BuiltinType{Kind: ast.Float128}},
+		{"Complex", mockComplexType(0), ast.BuiltinType{Kind: ast.Complex}},
+		{"Complex", mockComplexType(ast.Double), ast.BuiltinType{Flags: ast.Double, Kind: ast.Complex}},
+		{"Complex", mockComplexType(ast.Long | ast.Double), ast.BuiltinType{Flags: ast.Long | ast.Double, Kind: ast.Complex}},
 		{"Unknown", btType(clang.TypeIbm128), ast.BuiltinType{Kind: ast.Void}},
 	}
 
 	converter := &parse.Converter{}
 	converter.Convert()
 	for _, bt := range tests {
-		res := converter.ProcessBuiltinType(*bt.typ)
+		res := converter.ProcessBuiltinType(bt.typ)
 		if res.Kind != bt.expected.Kind {
 			fmt.Printf("%s Kind mismatch:got %d want %d, \n", bt.name, res.Kind, bt.expected.Kind)
 		}
@@ -57,6 +61,44 @@ func TestBuiltinType() {
 	}
 }
 
-func btType(kind clang.TypeKind) *clang.Type {
-	return &clang.Type{Kind: kind}
+func btType(kind clang.TypeKind) clang.Type {
+	return clang.Type{Kind: kind}
+}
+
+func visit(cursor, parent clang.Cursor, clientData unsafe.Pointer) clang.ChildVisitResult {
+	typ := (*clang.Type)(clientData)
+	if cursor.Kind == clang.CursorVarDecl && cursor.Type().Kind == clang.TypeComplex {
+		*typ = cursor.Type()
+	}
+	return clang.ChildVisit_Continue
+}
+
+// mock complex type, this type cannot be directly created in Go
+func mockComplexType(flag ast.TypeFlag) clang.Type {
+	var typeStr string
+	if flag&(ast.Long|ast.Double) == (ast.Long | ast.Double) {
+		typeStr = "long double"
+	} else if flag&ast.Double != 0 {
+		typeStr = "double"
+	} else {
+		typeStr = "float"
+	}
+
+	code := fmt.Sprintf("#include <complex.h>\n%s complex z;", typeStr)
+	index, unit, err := parse.CreateTranslationUnit(&parse.Config{
+		File: code,
+		Temp: true,
+		Args: []string{"-x", "c", "-std=c99"},
+	})
+	if err != nil {
+		panic(err)
+	}
+
+	defer index.Dispose()
+
+	cursor := unit.Cursor()
+	complex := &clang.Type{}
+	clang.VisitChildren(cursor, visit, unsafe.Pointer(complex))
+
+	return *complex
 }