diff --git a/lib/util/util_net.c b/lib/util/util_net.c
index d52d401e4c7..57db4fae4d8 100644
--- a/lib/util/util_net.c
+++ b/lib/util/util_net.c
@@ -53,7 +53,7 @@ static char *normalize_ipv6_literal(const char *str, char *buf, size_t *_len)
 	size_t cnt_chars = 0;
 
 	if (len <= llen) {
-		return false;
+		return NULL;
 	}
 
 	/* ignore a trailing '.' */