diff --git a/patch_yum_repo.sh b/patch_yum_repo.sh
index b771ec2..7852c3a 100755
--- a/patch_yum_repo.sh
+++ b/patch_yum_repo.sh
@@ -6,6 +6,6 @@ sed -i s/mirror.centos.org/vault.centos.org/g /etc/yum.repos.d/*.repo
 sed -i s/^#.*baseurl=http/baseurl=http/g /etc/yum.repos.d/*.repo
 sed -i s/^mirrorlist=http/#mirrorlist=http/g /etc/yum.repos.d/*.repo
 
-if [[ "$ARCH" = "aarch64" ]]; then
+if [[ "$(arch)" = "aarch64" ]]; then
     sed -i s/vault.centos.org\\/centos/vault.centos.org\\/altarch/g /etc/yum.repos.d/*.repo
 fi