diff --git a/src/common/general-tree.c b/src/common/general-tree.c
index e1048e72d2cde8730a6d4286bcc6e2da6b3c5f51..1edd0f3d0dde9e44c2f171fdb796d5de3e740a72 100644
--- a/src/common/general-tree.c
+++ b/src/common/general-tree.c
@@ -141,6 +141,7 @@ void gen_tree_clear(general_tree_t *tree)
 {
 	MOD_TREE_DESTROY(tree->tree, general_tree_node, avl, NULL,
 	                 gen_rem_func, NULL);
+	tree->tree->th_root = NULL; /* Invalidate tree root. */
 }
 
 //static void add_node_to_tree(void *n, void *data)