diff --git a/vars/build.vars b/vars/build.vars
index b69ce9d..4d71722 100644
--- a/vars/build.vars
+++ b/vars/build.vars
@@ -511,7 +511,7 @@ LEAF_PACKAGES_CONFIGURE_ARGS="-C --disable-nls --host=${TARGET} --prefix= --targ
 LEAF_PACKAGES_LDFLAGS_CONFIGURE="--sysroot=${PREFIX_NATIVE}";
 LEAF_PACKAGES_MAKEFLAGS_INSTALL="DESTDIR=${PREFIX_NATIVE}";
 LEAF_PACKAGES_PACKAGES="
-apk_tools bash bash_flavour_minipix bc bdwgc bind chicken clang_host coreutils coreutils_flavour_minipix
+apk_tools bash bash_flavour_minipix bc bdwgc bind bison chicken clang_host coreutils coreutils_flavour_minipix
 cparser cron dash datamash diffutils dos2unix ed figlet file findutils gawk git gnupg grep hexcurse htop
 inetutils infounzip infozip irssi john ldns less lighttpd lynx make man_db mc mksh mtr nano netcat nginx
 openlitespeed openssh p7zip pacman patch perl procps_ng python3 qpdf rsync rxvt_unicode sed smallbasic socat
@@ -541,6 +541,9 @@ LEAF_PACKAGES_PREFIX="${PREFIX_NATIVE}";
 : ${PKG_BIND_URL:=https://www.isc.org/downloads/file/bind-9-11-0-p2/};
 : ${PKG_BIND_CONFIGURE_ARGS_EXTRA:="--with-ecdsa=yes --with-gost=yes --with-gssapi=no --with-libtool --with-libxml2=${PREFIX}/bin/${TARGET}-xml2-config --with-libjson=no --with-openssl=${PREFIX_NATIVE} --with-randomdev=/dev/urandom BUILD_CC=gcc"};
 : ${PKG_BIND_FNAME:=bind-${PKG_BIND_VERSION}.tar.gz};
+: ${PKG_BISON_SHA256SUM:=a72428c7917bdf9fa93cb8181c971b6e22834125848cf1d03ce10b1bb0716fe1};
+: ${PKG_BISON_VERSION:=3.0.4};
+: ${PKG_BISON_URL:=https://ftp.gnu.org/gnu/bison/bison-3.0.4.tar.xz};
 : ${PKG_CHICKEN_SHA256SUM:=e3dc2b8f95b6a3cd59c85b5bb6bdb2bd9cefc45b5d536a20cad74e3c63f4ad89};
 : ${PKG_CHICKEN_VERSION:=4.11.0};
 : ${PKG_CHICKEN_URL:=https://code.call-cc.org/releases/4.11.0/chicken-${PKG_CHICKEN_VERSION}.tar.gz};