diff --git a/etc/build.sh b/etc/build.sh
index d8b62a10..d2312959 100755
--- a/etc/build.sh
+++ b/etc/build.sh
@@ -1,9 +1,12 @@
-#!/usr/bin/zsh
-project_root=$(dirname $(pwd))
-for f in ${project_root}/src/*.c ${project_root}/extlib/benz/*.c ${project_root}/contrib/**/*.c;do
-    cc -c -O2 -pg -std=c99  -I${project_root}/extlib/benz/include $f -o `basename $f`.o &
+#!/bin/sh
+set -e
+: ${GCC:=gcc}
+project_root=$(cd $(dirname $0); cd ../; pwd)
+
+for f in ${project_root}/src/*.c ${project_root}/extlib/benz/*.c $(find ${project_root}/contrib/* -name '*.c');do
+    ${GCC} -c -O2 -pg -std=c99  -I${project_root}/extlib/benz/include $f -o `basename $f`.o &
 done
 wait
-cc main.c.o $(find . -maxdepth 1 -name '*.o' | grep -v main.c.o | grep -v load_piclib.c.o | grep -v init_contrib.c.o) load_piclib.c.o init_contrib.c.o \
+${GCC} main.c.o $(find . -maxdepth 1 -name '*.o' | grep -v main.c.o | grep -v load_piclib.c.o | grep -v init_contrib.c.o) load_piclib.c.o init_contrib.c.o \
    -O2 -I${project_root}/extlib/benz/include -std=c99 -pg -lm -lreadline -o picrin
 rm *.o