diff --git a/chore/llcppg/llcppg.go b/chore/llcppg/llcppg.go
index e0e9745d..aba5b9d9 100644
--- a/chore/llcppg/llcppg.go
+++ b/chore/llcppg/llcppg.go
@@ -36,13 +36,14 @@ func llcppsymg(conf []byte) error {
 	return cmd.Run()
 }
 
-func llcppsigfetch(conf []byte, out io.Writer) {
+func llcppsigfetch(conf []byte, out *io.PipeWriter) {
 	cmd := exec.Command("llcppsigfetch", "-")
 	cmd.Stdin = bytes.NewReader(conf)
 	cmd.Stdout = out
 	cmd.Stderr = os.Stderr
 	err := cmd.Run()
 	check(err)
+	out.Close()
 }
 
 func gogensig(in io.Reader) error {