diff --git a/include/cln/config.h.in b/include/cln/config.h.in
index f1c7c3d..511d534 100644
--- a/include/cln/config.h.in
+++ b/include/cln/config.h.in
@@ -1,4 +1,5 @@
-#ifdef _CL_CONFIG_PUBLIC_H
+#ifndef _CL_CONFIG_PUBLIC_H
+#define _CL_CONFIG_PUBLIC_H
 
 #include "cln/host_cpu.h"
 #include "cln/version.h"