diff --git a/vars/build.vars b/vars/build.vars
index 1aa48a5..fdc342c 100644
--- a/vars/build.vars
+++ b/vars/build.vars
@@ -200,7 +200,7 @@ HOST_TOOLS_PREFIX="${PREFIX}";
 HOST_TOOLS_DEPS_BUILD_TYPE="host";
 HOST_TOOLS_DEPS_CONFIGURE_ARGS="--disable-nls --prefix=${PREFIX}";
 HOST_TOOLS_DEPS_MAKEFLAGS_INSTALL_EXTRA="prefix=";
-HOST_TOOLS_DEPS_PACKAGES="file_host libz_host";
+HOST_TOOLS_DEPS_PACKAGES="file_host libz_host m4_host";
 HOST_TOOLS_DEPS_PARALLELISE=0;
 HOST_TOOLS_DEPS_PREFIX="${PREFIX}";
 : ${PKG_FILE_HOST_SHA256SUM:=8639dc4d1b21e232285cd483604afc4a6ee810710e00e579dbe9591681722b50};
@@ -211,6 +211,9 @@ HOST_TOOLS_DEPS_PREFIX="${PREFIX}";
 : ${PKG_LIBZ_HOST_URL:=https://sortix.org/libz/release/libz-${PKG_LIBZ_HOST_VERSION}.tar.gz};
 : ${PKG_LIBZ_HOST_CONFIGURE_ARGS:="--prefix= --enable-shared"};
 : ${PKG_LIBZ_HOST_MAKEFLAGS_INSTALL:="PREFIX= prefix="};
+: ${PKG_M4_HOST_SHA256SUM:=f2c1e86ca0a404ff281631bdc8377638992744b175afb806e25871a24a934e07};
+: ${PKG_M4_HOST_VERSION:=1.4.18};
+: ${PKG_M4_HOST_URL:=https://ftp.gnu.org/gnu/m4/m4-${PKG_M4_HOST_VERSION}.tar.xz};
 
 #
 # Build target host_tools_rpm