1 files changed, 1 insertions, 0 deletions
diff --git a/configure b/configure
index 5b9daf7..b9ddeb9 100755
--- a/configure
+++ b/configure
@@ -309,6 +309,7 @@ write_makefiles()
 	# Make a script to edit input makefiles.
 	_sed_script=''
 	for _var in ${subst_vars}; do
+		_var="$(printf '%s' "${_var}" | tr -c '[a-z0-9]' '_')"
 		_sed_script="${_sed_script}s&@${_var}@&$(eval echo \$\{"${_var}"\})&g;"
 	done