diff --git a/cl/_testrt/qsortfn/in.go b/cl/_testrt/qsortfn/in.go
index fb527a04..dfc9c058 100644
--- a/cl/_testrt/qsortfn/in.go
+++ b/cl/_testrt/qsortfn/in.go
@@ -7,7 +7,7 @@ import (
 	q "github.com/goplus/llgo/cl/internal/qsort"
 )
 
-// llgo:type C
+//llgo:type C
 type Comp func(a, b c.Pointer) c.Int
 
 //go:linkname qsort C.qsort
diff --git a/cl/builtin_test.go b/cl/builtin_test.go
index 7c350d2f..5c479af5 100644
--- a/cl/builtin_test.go
+++ b/cl/builtin_test.go
@@ -27,6 +27,12 @@ import (
 	"golang.org/x/tools/go/ssa"
 )
 
+func TestToBackground(t *testing.T) {
+	if v := toBackground(""); v != llssa.InGo {
+		t.Fatal("toBackground:", v)
+	}
+}
+
 func TestCollectSkipNames(t *testing.T) {
 	ctx := &context{skips: make(map[string]none)}
 	ctx.collectSkipNames("//llgo:skipall")