diff --git a/mie/attribute/attribute-map.c b/mie/attribute/attribute-map.c
index 1d6d4ba..b33e265 100644
--- a/mie/attribute/attribute-map.c
+++ b/mie/attribute/attribute-map.c
@@ -149,6 +149,7 @@ enum mie_status mie_attribute_map_put(
 	struct attribute_map_entry *entry = get_entry(&map->m_entries, name_hash);
 	struct attribute_map_item *item = NULL;
 	struct attribute_map_bucket *bucket = NULL;
+	enum mie_status status = MIE_SUCCESS;
 
 	if (!entry) {
 		item = create_item(name, name_hash, value);
@@ -162,6 +163,17 @@ enum mie_status mie_attribute_map_put(
 
 	if (entry->e_type == ATTRMAP_ENTRY_ITEM) {
 		item = (struct attribute_map_item *)entry;
+		if (!strcmp(item->i_name, name)) {
+			status = MIE_ERR_NAME_EXISTS;
+
+			if (flags & MIE_ATTRMAP_F_REPLACE) {
+				item->i_value = value;
+				status = MIE_SUCCESS;
+			}
+
+			return status;
+		}
+
 		bucket = convert_item_to_bucket(map, item);
 	} else {
 		bucket = (struct attribute_map_bucket *)entry;