diff --git a/src/firejail/landlock.c b/src/firejail/landlock.c
index 52a562d6e4f..fcbe895f766 100644
--- a/src/firejail/landlock.c
+++ b/src/firejail/landlock.c
@@ -80,7 +80,7 @@ int ll_is_supported(void) {
 	return ll_abi;
 }
 
-static int ll_create_full_ruleset() {
+static int ll_create_full_ruleset(void) {
 	if (!ll_is_supported())
 		return -1;