diff --git a/src/parser/parser.l b/src/parser/parser.l
index 4f7f693..e68b5c7 100644
--- a/src/parser/parser.l
+++ b/src/parser/parser.l
@@ -117,6 +117,8 @@ L?'\\n'             (void)'\n'; return TOK_CHAR_CONST;
 L?'\\r'             (void)'\r'; return TOK_CHAR_CONST;
 L?'\\t'             (void)'\t'; return TOK_CHAR_CONST;
 L?'\\v'             (void)'\v'; return TOK_CHAR_CONST;
+L?'\\x[0-9A-Fa-f]{2}'   return TOK_CHAR_CONST;
+L?'\\[0-7]{1,3}'        return TOK_CHAR_CONST;
 [0-9]+([uU][lL]?[lL]?)?              return TOK_INT_CONST;
 0[xX][0-9a-fA-F]+([uU][lL]?[lL]?)?   return TOK_INT_CONST;
 ([0-9]+\.[0-9]*|\.[0-9]+)([eE][-+]?[0-9]+)?[fFlL]?     return TOK_FLOAT_CONST;