diff --git a/build.sh b/build.sh
index c6d9699..471eafd 100755
--- a/build.sh
+++ b/build.sh
@@ -70,7 +70,7 @@ for __ in ${CHECK_PATH_VARS}; do
 		log_msg failexit "Error: variable \`${__}' contains one or more whitespace characters.";
 	fi;
 done;
-for __ in ${CHECK_PREREQ_CMDS} ${CHECK_PREREQ_FILES}; do
+for __ in ${CHECK_PREREQ_CMDS} $(eval echo ${CHECK_PREREQ_FILES_DYNAMIC}) ${CHECK_PREREQ_FILES}; do
 	if [ "${__#/}" != "${__}" ]; then
 		if [ ! -e "${__}" ]; then
 			log_msg fail "Error: missing prerequisite file \`${__}'.";
diff --git a/build.vars b/build.vars
index d44354a..f4c62e1 100644
--- a/build.vars
+++ b/build.vars
@@ -43,6 +43,7 @@ export PATH="${PREFIX}/bin${PATH:+:${PATH}}";
 : ${BUILD_STATUS_IN_PROGRESS_FNAME:=${PREFIX}/BUILD_IN_PROGRESS};
 : ${CHECK_PREREQ_CMDS:="aclocal autoconf autopoint awk basename bunzip2 find flex git groff gunzip install libtool lzma make makeinfo msgfmt nl nroff openssl patch sed sha256sum sort tar tee tr uname wget xz"};
 : ${CHECK_PREREQ_FILES:="/usr/include/gmpxx.h /usr/include/mpc.h /usr/include/mpfr.h"};
+: ${CHECK_PREREQ_FILES_DYNAMIC:='/usr/share/groff/$(groff -v | awk '\''/^GNU groff version /{print $NF}'\'')/tmac/e.tmac'};
 : ${CHECK_PREREQ_PERL_MODULES:="autodie ExtUtils::MakeMaker"};
 : ${CHECK_PATH_VARS:="PREFIX PREFIX_NATIVE PREFIX_CROSS DLCACHEDIR WORKDIR"};
 : ${CLEAR_ENV_VARS_EXCEPT:="ARG_TARBALL ARG_VERBOSE HOME PATH SHELL TERM USER"};