diff --git a/src/cluster-table.c b/src/cluster-table.c
index e317d69..1721559 100644
--- a/src/cluster-table.c
+++ b/src/cluster-table.c
@@ -17,11 +17,11 @@ static const size_t nr_cluster_sizes
 
 static int node_init(struct ec3_cluster_group *n)
 {
-	memset(n, 0x0, sizeof *n);
-
-	for (int i = 0; i < EC3_CLUSTERS_PER_GROUP + 1; i++) {
-		n->g_child_offsets[i] = b_i32_htob(EC3_INVALID_OFFSET);
-	}
+	memset(&n->g_nr_clusters, 0x0, sizeof n->g_nr_clusters);
+	memset(n->g_reserved, 0x0, sizeof n->g_reserved);
+	memset(n->g_clusters, 0x0, sizeof n->g_clusters);
+	memset(n->g_child_offsets, 0xFF, sizeof n->g_child_offsets);
+	memset(n->g_padding, 0x0, sizeof n->g_padding);
 
 	return 0;
 }
@@ -97,6 +97,12 @@ static long tree_alloc_node(struct b_tree *p)
 	return (long)len;
 }
 
+static void __node_init(struct b_tree *tree, b_tree_node *n)
+{
+	struct ec3_cluster_group *node = (struct ec3_cluster_group *)n;
+	node_init(node);
+}
+
 static unsigned long node_get_nr_entries(struct b_tree *tree, b_tree_node *n)
 {
 	struct ec3_cluster_group *node = (struct ec3_cluster_group *)n;
@@ -190,6 +196,7 @@ static const struct b_tree_ops cluster_table_ops = {
 	.tree_put_node = tree_put_node,
 	.tree_alloc_node = tree_alloc_node,
 
+	.node_init = __node_init,
 	.node_get_nr_entries = node_get_nr_entries,
 	.node_set_nr_entries = node_set_nr_entries,
 	.node_get_entry = node_get_entry,