diff --git a/SLS_C/include/sls/lexer.h b/SLS_C/include/sls/lexer.h
index 02abb63..32faee2 100644
--- a/SLS_C/include/sls/lexer.h
+++ b/SLS_C/include/sls/lexer.h
@@ -6,5 +6,16 @@
 #ifndef SLS_LEXER_H
 #define SLS_LEXER_H
 
+typedef enum {
+    TOKEN_EOF,
+    TOKEN_IDENTIFIER,
+    TOKEN_INTEGER,
+    TOKEN_FLOAT,
+    TOKEN_STRING,
+    TOKEN_BOOLEAN,
+    TOKEN_ARRAY,
+    TOKEN_TOKEN_STRING,
+    TOKEN_TYPE_TUPLE,
+} TokenType;
 
 #endif // SLS_LEXER_H