diff --git a/servers/slapd/proto-slap.h b/servers/slapd/proto-slap.h
index f0c503b915..41594bb367 100644
--- a/servers/slapd/proto-slap.h
+++ b/servers/slapd/proto-slap.h
@@ -57,8 +57,9 @@ LDAP_SLAPD_F (AttributeDescription *) ad_dup LDAP_P((
 
 LDAP_SLAPD_F (void) ad_destroy LDAP_P(( AttributeDescription * ));
 
-#define ad_cmp(l,r)	(((l)->ad_cname.bv_len == (r)->ad_cname.bv_len) \
-	? strcasecmp((l)->ad_cname.bv_val, (r)->ad_cname.bv_val ) : 1 )
+#define ad_cmp(l,r)	(((l)->ad_cname.bv_len < (r)->ad_cname.bv_len) \
+	? -1 : (((l)->ad_cname.bv_len > (r)->ad_cname.bv_len) \
+		? strcasecmp((l)->ad_cname.bv_val, (r)->ad_cname.bv_val ) : 1 ))
 
 LDAP_SLAPD_F (int) is_ad_subtype LDAP_P((
 	AttributeDescription *sub,