diff --git a/src/scan.l b/src/scan.l
index 84a622eb..4e24ba8a 100644
--- a/src/scan.l
+++ b/src/scan.l
@@ -9,6 +9,8 @@
 
 #define YY_DECL int yylex_(YYSTYPE *yylvalp, yyscan_t yyscanner)
 
+#define yylval (*yylvalp)
+
 /* NOTE:
  *  An internal function `yy_fatal_error` takes yyscanner for its second
  * argument but doesn't use it. This invokes a `unused variable` compiler
@@ -70,16 +72,16 @@ infnan		"+inf.0"|"-inf.0"|"+nan.0"|"-nan.0"
 
 "#|"		{
   BEGIN(BLOCK_COMMENT);
-  yylvalp->i = 0;
+  yylval.i = 0;
 }
 <BLOCK_COMMENT>"#|" 	{
-  yylvalp->i++;
+  yylval.i++;
 }
 <BLOCK_COMMENT>"|#"	{
-  if (yylvalp->i == 0)
+  if (yylval.i == 0)
     BEGIN(INITIAL);
   else
-    yylvalp->i--;
+    yylval.i--;
 }
 <BLOCK_COMMENT>.|\n	{
   /* skip block comment */
@@ -98,23 +100,23 @@ infnan		"+inf.0"|"-inf.0"|"+nan.0"|"-nan.0"
 ",@"		return tUNQUOTE_SPLICING;
 
 {boolean}	{
-  yylvalp->i = (yytext[1] == 't');
+  yylval.i = (yytext[1] == 't');
   return tBOOLEAN;
 }
 
 {integer}	{
-  yylvalp->i = atoi(yytext);
+  yylval.i = atoi(yytext);
   return tINT;
 }
 
 {real} 		{
-  yylvalp->f = atof(yytext);
+  yylval.f = atof(yytext);
   return tFLOAT;
 }
 
 {identifier}	{
-  yylvalp->str.buf = yytext;
-  yylvalp->str.len = yyleng;
+  yylval.str.buf = yytext;
+  yylval.str.len = yyleng;
   return tSYMBOL;
 }
 
@@ -125,8 +127,8 @@ infnan		"+inf.0"|"-inf.0"|"+nan.0"|"-nan.0"
   yymore();
 }
 <STRING>"\""	{
-  yylvalp->str.buf = yytext;
-  yylvalp->str.len = yyleng - 1;
+  yylval.str.buf = yytext;
+  yylval.str.len = yyleng - 1;
   BEGIN(INITIAL);
   return tSTRING;
 }
@@ -134,22 +136,22 @@ infnan		"+inf.0"|"-inf.0"|"+nan.0"|"-nan.0"
 #\\		{
   BEGIN(CHAR);
 }
-<CHAR>alarm	{ yylvalp->c = '\a'; BEGIN(INITIAL); return tCHAR; }
-<CHAR>backspace	{ yylvalp->c = '\b'; BEGIN(INITIAL); return tCHAR; }
-<CHAR>delete	{ yylvalp->c = 0x7f; BEGIN(INITIAL); return tCHAR; }
-<CHAR>escape	{ yylvalp->c = 0x1b; BEGIN(INITIAL); return tCHAR; }
-<CHAR>newline	{ yylvalp->c = '\n'; BEGIN(INITIAL); return tCHAR; }
-<CHAR>null	{ yylvalp->c = '\0'; BEGIN(INITIAL); return tCHAR; }
-<CHAR>return	{ yylvalp->c = '\r'; BEGIN(INITIAL); return tCHAR; }
-<CHAR>space	{ yylvalp->c = ' ';  BEGIN(INITIAL); return tCHAR; }
-<CHAR>tab	{ yylvalp->c = '\t'; BEGIN(INITIAL); return tCHAR; }
-<CHAR>.		{ yylvalp->c = yytext[0]; BEGIN(INITIAL); return tCHAR; }
+<CHAR>alarm	{ yylval.c = '\a'; BEGIN(INITIAL); return tCHAR; }
+<CHAR>backspace	{ yylval.c = '\b'; BEGIN(INITIAL); return tCHAR; }
+<CHAR>delete	{ yylval.c = 0x7f; BEGIN(INITIAL); return tCHAR; }
+<CHAR>escape	{ yylval.c = 0x1b; BEGIN(INITIAL); return tCHAR; }
+<CHAR>newline	{ yylval.c = '\n'; BEGIN(INITIAL); return tCHAR; }
+<CHAR>null	{ yylval.c = '\0'; BEGIN(INITIAL); return tCHAR; }
+<CHAR>return	{ yylval.c = '\r'; BEGIN(INITIAL); return tCHAR; }
+<CHAR>space	{ yylval.c = ' ';  BEGIN(INITIAL); return tCHAR; }
+<CHAR>tab	{ yylval.c = '\t'; BEGIN(INITIAL); return tCHAR; }
+<CHAR>.		{ yylval.c = yytext[0]; BEGIN(INITIAL); return tCHAR; }
 
 "#u8("		{
   BEGIN(BYTEVECTOR);
-  yylvalp->blob.len = 0;
-  yylvalp->blob.capa = 10;
-  yylvalp->blob.dat = calloc(10, 1);
+  yylval.blob.len = 0;
+  yylval.blob.capa = 10;
+  yylval.blob.dat = calloc(10, 1);
 }
 <BYTEVECTOR>[ \r\n\t]	{
   /* skip whitespace */
@@ -158,10 +160,10 @@ infnan		"+inf.0"|"-inf.0"|"+nan.0"|"-nan.0"
   int i = atoi(yytext);
   if (0 > i || i > 255)
     REJECT;
-  yylvalp->blob.dat[yylvalp->blob.len++] = (char)i;
-  if (yylvalp->blob.len > yylvalp->blob.capa) {
-    yylvalp->blob.capa *= 2;
-    yylvalp->blob.dat = yyrealloc(yylvalp->blob.dat, yylvalp->blob.capa, yyscanner);
+  yylval.blob.dat[yylval.blob.len++] = (char)i;
+  if (yylval.blob.len > yylval.blob.capa) {
+    yylval.blob.capa *= 2;
+    yylval.blob.dat = yyrealloc(yylval.blob.dat, yylval.blob.capa, yyscanner);
   }
 }
 <BYTEVECTOR>")"	{