diff --git a/autotest/test.c b/autotest/test.c
index 315690e..4fac21f 100644
--- a/autotest/test.c
+++ b/autotest/test.c
@@ -732,7 +732,8 @@ int main(int argc, char** argv)
 	exotic_add_test(&handle, &exotic_test_rbtree_size_4, "rbtree_size_4");
 	exotic_add_test(&handle, &exotic_test_rbtree_check_10000, "rbtree_check_10000");
 	exotic_add_test(&handle, &exotic_test_rbtree_iterate_10000, "rbtree_iterate_10000");
-	exotic_add_test(&handle, &exotic_test_rbtree_remove_5000, "rbtree_remove_5000");
+	exotic_add_test(&handle, &exotic_test_rbtree_remove_10000, "rbtree_remove_10000");
+	exotic_add_test(&handle, &exotic_test_rbtree_destroy_1, "rbtree_destroy_1");
 	exotic_add_test(&handle, &exotic_test_sid_create_pool, "sid_create_pool");
 	exotic_add_test(&handle, &exotic_test_sid_check_0a, "sid_check_0a");
 	exotic_add_test(&handle, &exotic_test_sid_check_0b, "sid_check_0b");
@@ -770,6 +771,7 @@ int main(int argc, char** argv)
 	exotic_add_test(&handle, &exotic_test_timer_add_5_events_1, "timer_add_5_events_1");
 	exotic_add_test(&handle, &exotic_test_timer_check_5_events_1, "timer_check_5_events_1");
 	exotic_add_test(&handle, &exotic_test_timer_process_5_events_1, "timer_process_5_events_1");
+	exotic_add_test(&handle, &exotic_test_timer_shutdown, "timer_shutdown");
 	exotic_add_test(&handle, &exotic_test_tokenizer_basic_0, "tokenizer_basic_0");
 	exotic_add_test(&handle, &exotic_test_tokenizer_basic_1, "tokenizer_basic_1");
 	exotic_add_test(&handle, &exotic_test_tokenizer_basic_1a, "tokenizer_basic_1a");
diff --git a/autotest/test_rbtree.tcc b/autotest/test_rbtree.tcc
index 6a60aae..6ae76af 100644
--- a/autotest/test_rbtree.tcc
+++ b/autotest/test_rbtree.tcc
@@ -86,7 +86,7 @@ EXO_TEST(rbtree_size_3, { return rb_tree_size(tree) == 0; });
 
 EXO_TEST(rbtree_insert_10000, {
 	int i;
-	for (i = 0; i < MAX_NODES ; i++)
+	for (i = 0; i < MAX_NODES; i++)
 	{
 		const char* key = strdup(uhub_itoa(i));
 		const char* val = strdup(uhub_itoa(i + 16384));
@@ -96,11 +96,11 @@ EXO_TEST(rbtree_insert_10000, {
 	return 1;
 });
 
-EXO_TEST(rbtree_size_4, { return rb_tree_size(tree) == MAX_NODES ; });
+EXO_TEST(rbtree_size_4, { return rb_tree_size(tree) == MAX_NODES; });
 
 EXO_TEST(rbtree_check_10000, {
 	int i;
-	for (i = 0; i < MAX_NODES ; i++)
+	for (i = 0; i < MAX_NODES; i++)
 	{
 		char* key = strdup(uhub_itoa(i));
 		const char* expect = uhub_itoa(i + 16384);
@@ -116,29 +116,35 @@ EXO_TEST(rbtree_iterate_10000, {
 	struct rb_node* n = (struct rb_node*) rb_tree_first(tree);
 	while (n)
 	{
-		struct rb_node* p = n;
 		n = (struct rb_node*) rb_tree_next(tree);
 		i++;
 	}
-	return i == MAX_NODES ;
+	return i == MAX_NODES;
 });
 
-
+static int freed_nodes = 0;
 static void free_node(struct rb_node* n)
 {
 	hub_free((void*) n->key);
 	hub_free((void*) n->value);
+	freed_nodes += 1;
 }
 
-EXO_TEST(rbtree_remove_5000, {
-	int i = 0;
-	struct rb_node* n = (struct rb_node*) rb_tree_first(tree);
-	for (i = 0; i < MAX_NODES ; i += 2)
+EXO_TEST(rbtree_remove_10000, {
+	int i;
+	int j;
+	for (j = 0; j < 2; j++)
 	{
-		const char* key = uhub_itoa(i);
-		rb_tree_remove_node(tree, key, &free_node);
+		for (i = j; i < MAX_NODES; i += 2)
+		{
+			const char* key = uhub_itoa(i);
+			rb_tree_remove_node(tree, key, &free_node);
+		}
 	}
-	return 1;
+	return freed_nodes == MAX_NODES;
 });
 
-
+EXO_TEST(rbtree_destroy_1, {
+	rb_tree_destroy(tree);
+	return 1;
+});
diff --git a/autotest/test_timer.tcc b/autotest/test_timer.tcc
index 88d992a..75e7d51 100644
--- a/autotest/test_timer.tcc
+++ b/autotest/test_timer.tcc
@@ -117,3 +117,9 @@ EXO_TEST(timer_process_5_events_1,{
 	g_now = 4;
 	return timeout_queue_process(g_queue, g_now) == g_triggered;
 });
+
+EXO_TEST(timer_shutdown,{
+	timeout_queue_shutdown(g_queue);
+	hub_free(g_queue);
+	return 1;
+});
diff --git a/src/network/connection.c b/src/network/connection.c
index af4dbca..a96da10 100644
--- a/src/network/connection.c
+++ b/src/network/connection.c
@@ -283,7 +283,6 @@ static int net_connect_job_process(struct net_connect_job* job)
  */
 static void net_connect_job_internal_cb(struct net_connection* con, int event, void* ptr)
 {
-	int ret;
 	struct net_connect_job* job = net_con_get_ptr(con);
 	struct net_connect_job* next_job = job->next;
 	struct net_connect_handle* handle = job->handle;
@@ -441,7 +440,6 @@ static int net_con_connect_dns_callback(struct net_dns_job* job, const struct ne
 	struct net_connect_handle* handle = (struct net_connect_handle*) net_dns_job_get_ptr(job);
 	handle->dns = NULL;
 	size_t usable = 0;
-	int ret;
 
 	LOG_TRACE("net_con_connect(): async - Got DNS results");
 	if (!result)
diff --git a/src/network/dnsresolver.c b/src/network/dnsresolver.c
index 0484e9a..fd6ac91 100644
--- a/src/network/dnsresolver.c
+++ b/src/network/dnsresolver.c
@@ -99,9 +99,6 @@ void net_dns_initialize()
 
 void net_dns_destroy()
 {
-	struct net_dns_job* job;
-	struct net_dns_result* result;
-
 	uhub_mutex_lock(&g_dns->mutex);
 	LOG_TRACE("net_dns_destroy(): jobs=%d", (int) list_size(g_dns->jobs));
 	list_clear(g_dns->jobs, &shutdown_free_jobs);
diff --git a/src/util/rbtree.h b/src/util/rbtree.h
index 16a8093..2161d29 100644
--- a/src/util/rbtree.h
+++ b/src/util/rbtree.h
@@ -62,8 +62,8 @@ struct rb_tree
 extern struct rb_tree* rb_tree_create(rb_tree_compare compare, rb_tree_alloc alloc, rb_tree_free dealloc);
 
 /**
- * Deletes the tree and all the nodes.
- * But not the content inside the nodes.
+ * Delete the tree.
+ * Assumes that the tree is empty.
  */
 extern void rb_tree_destroy(struct rb_tree*);