diff --git a/.buildbot/deliver/01-sdist.sh b/.buildbot/deliver/01-sdist.sh
deleted file mode 100644
index bf60ef4..0000000
--- a/.buildbot/deliver/01-sdist.sh
+++ /dev/null
@@ -1,7 +0,0 @@
-python setup.py sdist --dist-dir . --formats gztar
-if test -n "$DIST_FILE" ; then
-	dist_name=`python setup.py --name`
-	dist_version=`python setup.py --version`
-	dist_file="${dist_name}-${dist_version}.tar.gz"
-	mv "$dist_file" "$DIST_FILE"
-fi
diff --git a/.buildbot/undist/01-unpack.sh b/.buildbot/undist/01-unpack.sh
new file mode 100644
index 0000000..a657e91
--- /dev/null
+++ b/.buildbot/undist/01-unpack.sh
@@ -0,0 +1,23 @@
+if test -z "$DIST_FORMAT" ; then
+	DIST_FORMAT="gztar"
+fi
+
+if test -z "$DIST_FILE" ; then
+	echo "Environment variable DIST_FILE must not be empty" >&2
+	exit 1
+fi
+
+if test -n "$INSTALL_DIR" ; then
+	mkdir -p "$INSTALL_DIR"
+	tar_opts="--strip-components=1 -C \"$INSTALL_DIR\""
+fi
+
+case "$DIST_FORMAT" in
+gztar)
+	tar -xzf "$DIST_FILE" $tar_opts
+	;;
+*)
+	echo "Unsupported DIST_FORMAT ($DIST_FORMAT)" >&2
+	exit 1
+	;;
+esac