diff --git a/buildlab.in b/buildlab.in
index 29795a3af022a0936c84c8c227e81caae3934270..cb4c368a99cf241916a44d592e823d4c83712f8a 100755
--- a/buildlab.in
+++ b/buildlab.in
@@ -94,40 +94,44 @@ prepare_chroot() {
 	msg "Setting up repositories for mirror $mirror with version $version at $path..."
 
 	mkdir -p "$path"/etc/apk
-	echo "http://$mirror/alpine/$version/packages/$arch/main" >> "$path"/etc/apk/repositories
-	echo "http://$mirror/alpine/$version/packages/$arch/testing" >> "$path"/etc/apk/repositories
+	echo "http://$mirror/alpine/$version/main" >> "$path"/etc/apk/repositories
+	echo "http://$mirror/alpine/$version/testing" >> "$path"/etc/apk/repositories
 
 	if [ ! -z "$enablecache" ]; then
 		mkdir -p "$path"/var/cache/apk
 		ln -s /var/cache/apk "$path"/etc/apk/cache
 	fi
 
-	mkdir -p "$path"/var/lib/apk
-	echo "alpine-base" > "$path"/var/lib/apk/world
+	echo "alpine-base" > "$path"/etc/apk/world
+	mkdir -p "$path"/lib/apk/db
+	mkdir -p "$path"/var/lock
+	mkdir -p "$path"/var/cache/apk
+	mkdir -p "$path"/tmp
 
 	mkdir -p "$path"/etc
 	cp /etc/resolv.conf "$path"/etc/resolv.conf
 
 	msg "Updating package lists..."
 
-	apk --root $path --repositories "$path"/etc/apk/repositories update
+	apk --arch $buildarch --root $path --repositories "$path"/etc/apk/repositories update
 
 	msg "Installing alpine-base..."
 
-	apk --root $path --repositories "$path"/etc/apk/repositories add --initdb alpine-base
+	apk --arch $buildarch --root $path --repositories "$path"/etc/apk/repositories add --initdb alpine-base
 
 	msg "Installing abuild..."
 
-	apk --root $path --repositories "$path"/etc/apk/repositories add --initdb abuild
+	apk --arch $buildarch --root $path --repositories "$path"/etc/apk/repositories add --initdb abuild
 
 	msg "Installing build-base..."
 
-	apk --root $path --repositories "$path"/etc/apk/repositories add --initdb build-base
+	apk --arch $buildarch --root $path --repositories "$path"/etc/apk/repositories add --initdb build-base
 
 	msg "Adding abuild user..."
 
 	do_chroot_action "$path" adduser -D -G abuild abuild
 	echo "abuild ALL=NOPASSWD: ALL" >> "$path"/etc/sudoers
+	chmod 440 "$path"/etc/sudoers
 
 	msg "Generating buildlab signing keys..."
 	do_chroot_action "$path" su abuild -c "'abuild-keygen -ai'"