diff --git a/sys/build.sh b/sys/build.sh
index f8319b8484..c91e916ef9 100755
--- a/sys/build.sh
+++ b/sys/build.sh
@@ -66,9 +66,6 @@ if [ "`uname`" = Darwin ]; then
 		[ "$(id -u)" = 0 ] || SUDO=sudo
 		[ -n "${NOSUDO}" ] && SUDO=
 	fi
-else
-	[ -n "${PREFIX}" -a "${PREFIX}" != /usr ] && \
-		CFGARG="${CFGARG} --with-rpath"
 fi
 
 [ -z "${PREFIX}" ] && PREFIX="${DEFAULT_PREFIX}"
@@ -96,6 +93,10 @@ if [ "${USE_CS5}" = 1 ]; then
 	CFGARG="${CFGARG} --with-capstone5"
 fi
 
+if [ "`uname`" != Darwin -a -n "${PREFIX}" -a "${PREFIX}" != /usr ]; then
+	CFGARG="${CFGARG} --with-rpath"
+fi
+
 ccache --help > /dev/null 2>&1
 if [ $? = 0 ]; then
 	[ -z "${CC}" ] && CC=gcc