diff --git a/vars/build.vars b/vars/build.vars
index 3a334f3..7eacc32 100644
--- a/vars/build.vars
+++ b/vars/build.vars
@@ -189,9 +189,11 @@ HOST_TOOLS_PREFIX="${PREFIX}";
 # Build group host_deps
 #
 HOST_DEPS_BUILD_TYPE="host";
-HOST_DEPS_CONFIGURE_ARGS="--disable-nls --prefix= --target=${DEFAULT_TARGET}";
+HOST_DEPS_CONFIGURE_ARGS="--disable-nls --prefix=${PREFIX}";
+HOST_DEPS_MAKEFLAGS_INSTALL="PREFIX= prefix=";
 HOST_DEPS_PACKAGES="
-bmake_host bzip2_host file_host install_strip_host libz_host mpackage_host sqlite3_host texinfo_host";
+bmake_host bzip2_host file_host bison_host flex_host install_strip_host
+libz_host mpackage_host sqlite3_host texinfo_host";
 HOST_DEPS_PARALLELISE=1;
 HOST_DEPS_PREFIX="${PREFIX}";
 : ${PKG_BMAKE_HOST_URLS_GIT:="bmake=https://github.com/arichardson/bmake@master"};
@@ -205,12 +207,17 @@ HOST_DEPS_PREFIX="${PREFIX}";
 : ${PKG_FILE_HOST_SHA256SUM:=8639dc4d1b21e232285cd483604afc4a6ee810710e00e579dbe9591681722b50};
 : ${PKG_FILE_HOST_VERSION:=5.32};
 : ${PKG_FILE_HOST_URL:=ftp://ftp.astron.com/pub/file/file-${PKG_FILE_HOST_VERSION}.tar.gz};
+: ${PKG_BISON_HOST_SHA256SUM:=55e4a023b1b4ad19095a5f8279f0dc048fa29f970759cea83224a6d5e7a3a641};
+: ${PKG_BISON_HOST_VERSION:=3.5};
+: ${PKG_BISON_HOST_URL:=https://ftp.gnu.org/gnu/bison/bison-${PKG_BISON_HOST_VERSION}.tar.xz};
+: ${PKG_FLEX_HOST_SHA256SUM:=68b2742233e747c462f781462a2a1e299dc6207401dac8f0bbb316f48565c2aa};
+: ${PKG_FLEX_HOST_VERSION:=2.6.3};
+: ${PKG_FLEX_HOST_URL:=https://github.com/westes/flex/releases/download/v${PKG_FLEX_HOST_VERSION}/flex-${PKG_FLEX_HOST_VERSION}.tar.gz};
 : ${PKG_INSTALL_STRIP_HOST_NO_LOG_VARS:=1};
 : ${PKG_LIBZ_HOST_SHA256SUM:=abcc2831b7a0e891d0875fa852e9b9510b420d843d3d20aad010f65493fe4f7b};
 : ${PKG_LIBZ_HOST_VERSION:=1.2.8.2015.12.26};
 : ${PKG_LIBZ_HOST_URL:=https://sortix.org/libz/release/libz-${PKG_LIBZ_HOST_VERSION}.tar.gz};
-: ${PKG_LIBZ_HOST_CONFIGURE_ARGS:="--prefix= --enable-shared"};
-: ${PKG_LIBZ_HOST_MAKEFLAGS_INSTALL:="PREFIX= prefix="};
+: ${PKG_LIBZ_HOST_CONFIGURE_ARGS:="--enable-shared"};
 : ${PKG_MPACKAGE_HOST_URLS_GIT:=mpackage=${DEFAULT_GITROOT}/mpackage};
 : ${PKG_MPACKAGE_HOST_MAKEFLAGS_BUILD:="DESTDIR=${PREFIX_NATIVE}"};
 : ${PKG_MPACKAGE_HOST_IN_TREE:=1};