diff --git a/build b/build
index 5f0b667..d882edc 100755
--- a/build
+++ b/build
@@ -5,6 +5,7 @@ if [ "${BASH_VERSINFO[0]}" -lt 4 ]; then
 	exit 1
 fi
 
+declare -r OS=$(uname -s)
 declare	BOOTSTRAP_DIR=$(dirname "$0")
 source "${BOOTSTRAP_DIR}/Pmodules/libstd.bash" || { echo "Oops!" 1>&2; exit 42; }