diff --git a/SLS_C/include/sls/lexer.h b/SLS_C/include/sls/lexer.h
index 32faee2..b5920f8 100644
--- a/SLS_C/include/sls/lexer.h
+++ b/SLS_C/include/sls/lexer.h
@@ -6,6 +6,8 @@
 #ifndef SLS_LEXER_H
 #define SLS_LEXER_H
 
+#include <stdint.h>
+
 typedef enum {
     TOKEN_EOF,
     TOKEN_IDENTIFIER,
@@ -18,4 +20,9 @@ typedef enum {
     TOKEN_TYPE_TUPLE,
 } TokenType;
 
+typedef struct {
+    const char *name;
+    uint8_t is_literal;
+} Identifier;
+
 #endif // SLS_LEXER_H