1 files changed, 6 insertions, 0 deletions
diff --git a/lex.h b/lex.h
index 6c4f819..4c6662b 100644
--- a/lex.h
+++ b/lex.h
@@ -1,3 +1,8 @@
+#ifndef HENCE_LEX_H
+#define HENCE_LEX_H
+
+#include <stdio.h>
+
 #define MAX_IDENT_LENGTH 128
 
 enum TOKEN_TYPE {
@@ -35,3 +40,4 @@ struct token {
 struct token* lex_file(FILE*);
 const char *get_token_description(enum TOKEN_TYPE);
 
+#endif