diff --git a/thickenings.c b/thickenings.c
index 8398f21..1ef6f19 100644
--- a/thickenings.c
+++ b/thickenings.c
@@ -224,31 +224,34 @@ void prepare_graph(semisimple_type_t type, node_t *graph, edgelist_t **edgelists
 
   for(int i = 0; i < order; i++) {
     memset(seen, 0, order*sizeof(int));
-    for(int len = 1; len <= max_wordlength; len++) {
+    queue_init(&queue);
+
+    for(int len = 1; len <= graph[i].wordlength; len++) {
       // remove all edges originating from i of length len which connect to something already seen using shorter edges
       edge = graph[i].bruhat_lower;
       previous = (edgelist_t*)0;
+
       while(edge) {
-	if(seen[edge->to] && graph[i].wordlength - graph[edge->to].wordlength == len) {
-	  //	  fprintf(stderr, "deleting from %d to %d\n", i, edge->to);
+	if(graph[i].wordlength - graph[edge->to].wordlength != len) {
+	  previous = edge;
+	} else if(seen[edge->to]) {
 	  if(previous)
 	    previous->next = edge->next;
 	  else
 	    graph[i].bruhat_lower = edge->next;
 	} else {
 	  previous = edge;
+	  seen[edge->to] = 1;
+	  queue_put(&queue, edge->to);
 	}
 	edge = edge->next;
       }
 
       // see which nodes we can reach using only edges up to length len, mark them as seen
-      queue_init(&queue);
-      queue_put(&queue, i);
-      seen[i] = 1;
       while((current = queue_get(&queue)) != -1) {
 	edge = graph[current].bruhat_lower;
 	while(edge) {
-	  if(!seen[edge->to] && graph[current].wordlength - graph[edge->to].wordlength == len) {
+	  if(!seen[edge->to]) {
 	    seen[edge->to] = 1;
 	    queue_put(&queue, edge->to);
 	  }