diff --git a/src/parser/asts/functions.c b/src/parser/asts/functions.c
index ea60e1d..95cb6b8 100644
--- a/src/parser/asts/functions.c
+++ b/src/parser/asts/functions.c
@@ -7,6 +7,7 @@
 #include "../parser.h"
 #include "../ast.h"
 
+#include "../../lexer/tokens.h"
 #include "../../lexer/lexer.h"
 
 /**
diff --git a/src/parser/asts/functions.h b/src/parser/asts/functions.h
index 0564c80..cf05a1b 100644
--- a/src/parser/asts/functions.h
+++ b/src/parser/asts/functions.h
@@ -2,6 +2,8 @@
  * Function-related AST parsing.
  */
 
+#include "../../lexer/lexer.h"
+
 #include "../ast.h"
 
 #ifndef AST_FUNC_H
diff --git a/src/parser/asts/math.c b/src/parser/asts/math.c
index fada606..ca72818 100644
--- a/src/parser/asts/math.c
+++ b/src/parser/asts/math.c
@@ -4,6 +4,8 @@
 
 #include <stdlib.h>
 
+#include "../../lexer/lexer.h"
+
 #include "../ast.h"
 #include "./variables.h"
 
diff --git a/src/parser/parser.c b/src/parser/parser.c
index 1028f6d..6fce88c 100644
--- a/src/parser/parser.c
+++ b/src/parser/parser.c
@@ -4,7 +4,9 @@
 
 #include <stdio.h>
 
+#include "../lexer/tokens.h"
 #include "../lexer/lexer.h"
+
 #include "./ast.h"
 
 #include "./asts/variables.h"