diff --git a/src/parser/flex_lexer.l b/src/parser/flex_lexer.l
index a282807f..8e5adb44 100644
--- a/src/parser/flex_lexer.l
+++ b/src/parser/flex_lexer.l
@@ -227,7 +227,7 @@ CHARACTER[ \t\n]+VARYING TOKEN(CHARACTER_VARYING)
 
 [-+*/(){},.;<>=^%:?[\]|]    { return yytext[0]; }
 
-[0-9]+"."[0-9]* |
+-?[0-9]+"."[0-9]* |
 "."[0-9]*  {
   yylval->fval = atof(yytext);
   return SQL_FLOATVAL;
@@ -243,7 +243,7 @@ CHARACTER[ \t\n]+VARYING TOKEN(CHARACTER_VARYING)
   return SQL_INTVAL;
 }
 
-[0-9]+ {
+-?[0-9]+ {
   errno = 0;
   yylval->ival = strtoll(yytext, nullptr, 0);
   if (errno) {