diff --git a/diskimage_builder/elements/centos/pre-install.d/01-set-centos-mirror b/diskimage_builder/elements/centos/pre-install.d/01-set-centos-mirror
index 9abb9613..93cf814c 100755
--- a/diskimage_builder/elements/centos/pre-install.d/01-set-centos-mirror
+++ b/diskimage_builder/elements/centos/pre-install.d/01-set-centos-mirror
@@ -13,11 +13,11 @@ DIB_DISTRIBUTION_MIRROR=${DIB_DISTRIBUTION_MIRROR:-}
 # Only set the mirror for the Base, Extras and Updates repositories
 # The others aren't enabled and do not exist on all mirrors
 if [[ ${DIB_RELEASE} == '7' ]]; then
-    sed -e "s|^#baseurl=http[s]*://mirror.centos.org/centos|baseurl=$DIB_DISTRIBUTION_MIRROR|;/^mirrorlist=/d" -i /etc/yum.repos.d/CentOS-Base.repo
+    sed -e "s,^#baseurl=http[s]*://mirror.centos.org/\(centos\|altarch\)/,baseurl=$DIB_DISTRIBUTION_MIRROR/,;/^mirrorlist=/d" -i /etc/yum.repos.d/CentOS-Base.repo
 elif [[ ${DIB_RELEASE} == '8' ]]; then
-    sed -e "s|^#baseurl=http[s]*://mirror.centos.org/\$contentdir/|baseurl=$DIB_DISTRIBUTION_MIRROR/|;/^mirrorlist=/d" -i /etc/yum.repos.d/CentOS-Base.repo
-    sed -e "s|^#baseurl=http[s]*://mirror.centos.org/\$contentdir/|baseurl=$DIB_DISTRIBUTION_MIRROR/|;/^mirrorlist=/d" -i /etc/yum.repos.d/CentOS-AppStream.repo
-    sed -e "s|^#baseurl=http[s]*://mirror.centos.org/\$contentdir/|baseurl=$DIB_DISTRIBUTION_MIRROR/|;/^mirrorlist=/d" -i /etc/yum.repos.d/CentOS-centosplus.repo
-    sed -e "s|^#baseurl=http[s]*://mirror.centos.org/\$contentdir/|baseurl=$DIB_DISTRIBUTION_MIRROR/|;/^mirrorlist=/d" -i /etc/yum.repos.d/CentOS-Extras.repo
-    sed -e "s|^#baseurl=http[s]*://mirror.centos.org/\$contentdir/|baseurl=$DIB_DISTRIBUTION_MIRROR/|;/^mirrorlist=/d" -i /etc/yum.repos.d/CentOS-PowerTools.repo
+    sed -e "s,^#baseurl=http[s]*://mirror.centos.org/\$contentdir/,baseurl=$DIB_DISTRIBUTION_MIRROR/,;/^mirrorlist=/d" -i /etc/yum.repos.d/CentOS-Base.repo
+    sed -e "s,^#baseurl=http[s]*://mirror.centos.org/\$contentdir/,baseurl=$DIB_DISTRIBUTION_MIRROR/,;/^mirrorlist=/d" -i /etc/yum.repos.d/CentOS-AppStream.repo
+    sed -e "s,^#baseurl=http[s]*://mirror.centos.org/\$contentdir/,baseurl=$DIB_DISTRIBUTION_MIRROR/,;/^mirrorlist=/d" -i /etc/yum.repos.d/CentOS-centosplus.repo
+    sed -e "s,^#baseurl=http[s]*://mirror.centos.org/\$contentdir/,baseurl=$DIB_DISTRIBUTION_MIRROR/,;/^mirrorlist=/d" -i /etc/yum.repos.d/CentOS-Extras.repo
+    sed -e "s,^#baseurl=http[s]*://mirror.centos.org/\$contentdir/,baseurl=$DIB_DISTRIBUTION_MIRROR/,;/^mirrorlist=/d" -i /etc/yum.repos.d/CentOS-PowerTools.repo
 fi