diff --git a/frontend/debug.c b/frontend/debug.c
index 4bcab8f..5004c6a 100644
--- a/frontend/debug.c
+++ b/frontend/debug.c
@@ -1,3 +1,5 @@
+#include "debug.h"
+
 #include <blue/object/string.h>
 #include <blue/term.h>
 #include <ivy/asm/lex.h>
@@ -132,10 +134,23 @@ extern void print_asm_lex_token(struct ivy_asm_token *tok)
 }
 
 extern enum ivy_status print_ast_node(
-	struct ivy_ast_node *node, struct ivy_ast_node_iterator *it)
+	struct ivy_ast_node *node, enum ivy_ast_iteration_type type,
+	struct ivy_ast_node_iterator *it, void *arg)
 {
-	for (unsigned int i = 0; i < node->n_it.it_depth; i++) {
-		b_puts("  ");
+	struct print_ast_node_args *args = arg;
+
+	if (args && args->postorder && type != IVY_AST_ITERATION_POST) {
+		return IVY_OK;
+	}
+
+	if ((!args || !args->postorder) && type != IVY_AST_ITERATION_PRE) {
+		return IVY_OK;
+	}
+
+	if (!args || (args && args->indent)) {
+		for (unsigned int i = 0; i < node->n_it.it_depth; i++) {
+			b_puts("  ");
+		}
 	}
 
 	switch (node->n_type) {
diff --git a/frontend/debug.h b/frontend/debug.h
index 6884742..31c4df8 100644
--- a/frontend/debug.h
+++ b/frontend/debug.h
@@ -2,6 +2,7 @@
 #define DEBUG_H_
 
 #include <ivy/status.h>
+#include <stdbool.h>
 
 struct ivy_token;
 struct ivy_asm_token;
@@ -9,10 +10,18 @@ struct ivy_asm_token;
 struct ivy_ast_node;
 struct ivy_ast_node_iterator;
 
+enum ivy_ast_iteration_type;
+
+struct print_ast_node_args {
+	bool indent;
+	bool postorder;
+};
+
 extern void print_lex_token(struct ivy_token *tok);
 extern void print_asm_lex_token(struct ivy_asm_token *tok);
 
 extern enum ivy_status print_ast_node(
-	struct ivy_ast_node *node, struct ivy_ast_node_iterator *it);
+	struct ivy_ast_node *node, enum ivy_ast_iteration_type type,
+	struct ivy_ast_node_iterator *it, void *arg);
 
 #endif