diff --git a/tree.c b/tree.c
index 6339409..0b9c36e 100644
--- a/tree.c
+++ b/tree.c
@@ -109,13 +109,13 @@ void print_node(node, side, depth, details)
             if (node->type==TREE_NODE) {
                 printf("(");
             }
-            print_node(node->right, TREE_RIGHT, depth+1, details);
+            print_node(node->left, TREE_LEFT, depth+1, details);
             if (node->type==TREE_NODE) {
                 printf(" %c ", node->op);
             } else {
                 printf("%d", node->val);
             }
-            print_node(node->left, TREE_LEFT, depth+1, details);
+            print_node(node->right, TREE_RIGHT, depth+1, details);
             if (node->type==TREE_NODE) {
                 printf(")");
             }