diff --git a/doc/Changelog b/doc/Changelog
index accfaade9..d8f88f88c 100644
--- a/doc/Changelog
+++ b/doc/Changelog
@@ -1,3 +1,6 @@
+5 March 2021: Wouter
+	- Workaround for #439: prevent loops in the reuse rbtree.
+
 4 March 2021: Wouter
 	- iana portlist update.
 	- Fix spurious errors about "Could not generate request: out of
diff --git a/services/outside_network.c b/services/outside_network.c
index 18e2c8da9..d2d8c56f5 100644
--- a/services/outside_network.c
+++ b/services/outside_network.c
@@ -892,6 +892,9 @@ reuse_tcp_remove_tree_list(struct outside_network* outnet,
 		/* delete it from reuse tree */
 		(void)rbtree_delete(&outnet->tcp_reuse, reuse);
 		reuse->node.key = NULL;
+		/* defend against loops on broken tree by zeroing the
+		 * rbnode structure */
+		memset(&reuse->node, 0, sizeof(reuse->node));
 	}
 	/* delete from reuse list */
 	if(reuse->item_on_lru_list) {