diff --git a/src/Lexer.hpp b/src/Lexer.hpp
index e9d64f9..bc62548 100644
--- a/src/Lexer.hpp
+++ b/src/Lexer.hpp
@@ -1,5 +1,4 @@
-#ifndef LEXER_HPP
-#define LEXER_HPP
+#pragma once
 
 #include <ctype.h>
 #include "Token.hpp"
@@ -75,5 +74,3 @@ class Lexer
 
     Token nextToken();
 };
-
-#endif
diff --git a/src/List.hpp b/src/List.hpp
index c55312c..a6c2e8c 100644
--- a/src/List.hpp
+++ b/src/List.hpp
@@ -1,5 +1,4 @@
-#ifndef LIST_HPP
-#define LIST_HPP
+#pragma once
 
 #include <cstdarg>
 
@@ -77,5 +76,3 @@ class List {
 		this->size -= 1;
 	}
 };
-
-#endif
diff --git a/src/ParseTree.hpp b/src/ParseTree.hpp
index a98da62..70a8558 100644
--- a/src/ParseTree.hpp
+++ b/src/ParseTree.hpp
@@ -1,13 +1,10 @@
-#ifndef PARSETREE_HPP
-#define PARSETREE_HPP
+#pragma once
 
 #include "ParserRule.hpp"
 #include "Token.hpp"
-#include "Lexer.hpp"
 #include "String.hpp"
 #include "Vector.hpp"
 
-
 class ParseTree
 {
 protected:
@@ -396,5 +393,3 @@ class Prog : public ParseTree
     String typeCheck();
     String makeCode();
 };
-
-#endif