diff --git a/cl/_testrt/intgen/in.go b/cl/_testrt/intgen/in.go
index 2b7b2159..cb6b8a47 100644
--- a/cl/_testrt/intgen/in.go
+++ b/cl/_testrt/intgen/in.go
@@ -4,6 +4,15 @@ import (
 	"github.com/goplus/llgo/internal/runtime/c"
 )
 
+type generator struct {
+	val c.Int
+}
+
+func (g *generator) next() c.Int {
+	g.val++
+	return g.val
+}
+
 func genInts(n int, gen func() c.Int) []c.Int {
 	a := make([]c.Int, n)
 	for i := range a {
@@ -25,4 +34,8 @@ func main() {
 	for _, v := range b {
 		c.Printf(c.Str("%d\n"), v)
 	}
+	g := &generator{val: 1}
+	for _, v := range genInts(5, g.next) {
+		c.Printf(c.Str("%d\n"), v)
+	}
 }
diff --git a/cl/compile.go b/cl/compile.go
index 156e1825..059952d4 100644
--- a/cl/compile.go
+++ b/cl/compile.go
@@ -645,7 +645,8 @@ func (p *context) compileValue(b llssa.Builder, v ssa.Value) llssa.Expr {
 			}
 		}
 	case *ssa.Function:
-		if v.Pkg == p.goPkg { // function in this package
+		// v.Pkg == nil: means auto generated function?
+		if v.Pkg == p.goPkg || v.Pkg == nil { // function in this package
 			fn := p.compileFunc(p.pkg, p.goTyps, v)
 			return fn.Expr
 		}