diff --git a/src/event.c b/src/event.c
index 60d357d4..59b96e37 100644
--- a/src/event.c
+++ b/src/event.c
@@ -285,6 +285,16 @@ bool event_loop(void) {
 				io->cb(io->data, IO_WRITE);
 			else if(FD_ISSET(io->fd, &readable))
 				io->cb(io->data, IO_READ);
+			else
+				continue;
+
+			/*
+			   There are scenarios in which the callback will remove another io_t from the tree
+			   (e.g. closing a double connection). Since splay_each does not support that, we
+			   need to exit the loop now. That's okay, since any remaining events will get picked
+			   up by the next select() call.
+			 */
+			break;
 		}
 	}
 #else
diff --git a/src/list.h b/src/list.h
index 0437bd92..b0e7a845 100644
--- a/src/list.h
+++ b/src/list.h
@@ -79,6 +79,12 @@ extern void list_delete_list(list_t *);
 extern void list_foreach(list_t *, list_action_t);
 extern void list_foreach_node(list_t *, list_action_node_t);
 
+/*
+   Iterates over a list.
+
+   CAUTION: while this construct supports deleting the current item,
+   it does *not* support deleting *other* nodes while iterating on the list.
+ */
 #define list_each(type, item, list) (type *item = (type *)1; item; item = NULL) for(list_node_t *node = (list)->head, *next; item = node ? node->data : NULL, next = node ? node->next : NULL, node; node = next)
 
 #endif /* __TINC_LIST_H__ */
diff --git a/src/splay_tree.h b/src/splay_tree.h
index 58488707..3ddf2172 100644
--- a/src/splay_tree.h
+++ b/src/splay_tree.h
@@ -106,6 +106,12 @@ extern splay_node_t *splay_search_closest_greater_node(splay_tree_t *, const voi
 extern void splay_foreach(const splay_tree_t *, splay_action_t);
 extern void splay_foreach_node(const splay_tree_t *, splay_action_t);
 
+/*
+   Iterates over a tree.
+
+   CAUTION: while this construct supports deleting the current item,
+   it does *not* support deleting *other* nodes while iterating on the tree.
+ */
 #define splay_each(type, item, tree) (type *item = (type *)1; item; item = NULL) for(splay_node_t *node = (tree)->head, *next; item = node ? node->data : NULL, next = node ? node->next : NULL, node; node = next)
 
 #endif