diff --git a/lib/config/config_lexer.ll b/lib/config/config_lexer.ll
index 23b46deeb..a578707fb 100644
--- a/lib/config/config_lexer.ll
+++ b/lib/config/config_lexer.ll
@@ -98,6 +98,7 @@ static char *lb_steal(lex_buf *lb)
 %option reentrant noyywrap yylineno
 %option bison-bridge bison-locations
 %option never-interactive nounistd
+%option noinput nounput
 
 %x C_COMMENT
 %x STRING
diff --git a/tools/mkclass/class_lexer.ll b/tools/mkclass/class_lexer.ll
index 8ecf95da7..10f351be0 100644
--- a/tools/mkclass/class_lexer.ll
+++ b/tools/mkclass/class_lexer.ll
@@ -92,6 +92,7 @@ static char *lb_steal(lex_buf *lb)
 %option reentrant noyywrap yylineno
 %option bison-bridge bison-locations
 %option never-interactive nounistd
+%option noinput nounput
 
 %x HEREDOC
 %x C_COMMENT