diff --git a/libraries/liblber/options.c b/libraries/liblber/options.c
index 4546861619..c5f37812ba 100644
--- a/libraries/liblber/options.c
+++ b/libraries/liblber/options.c
@@ -57,7 +57,7 @@ int
 ber_set_option(
 	void	*item,
 	int		option,
-	void	*invalue)
+	LDAP_CONST void	*invalue)
 {
 	BerElement *ber;
 	Sockbuf *sb;