diff --git a/parser.y b/parser.y
index 835486cc..503d0df6 100644
--- a/parser.y
+++ b/parser.y
@@ -53,6 +53,7 @@ bool: '(' bool ')'  { $$ = $2; };
 #include "xmalloc.h"
 
 int yylex (YYSTYPE *lvalp, YYLTYPE *llocp, struct parser_context *ctx) {
+    (void)llocp;
     int c = ctx->input[ctx->pos];
 
     while (c == ' ' || c == '\t')
@@ -88,6 +89,9 @@ int yylex (YYSTYPE *lvalp, YYLTYPE *llocp, struct parser_context *ctx) {
 #include <stdio.h>
 
 void yyerror (YYLTYPE *locp, struct parser_context *ctx, char const *s) {
+    (void)locp;
+    (void)ctx;
+    (void)s;
 }