diff --git a/test/start-syncbased.sh b/test/start-syncbased.sh
index 8b2c99b..6cf9f24 100755
--- a/test/start-syncbased.sh
+++ b/test/start-syncbased.sh
@@ -9,5 +9,7 @@
 # does not allow flags or arguments to the executables it starts.  We should
 # fix service-runner to allow flags/arguments, and then have it start syncbased
 # directly with the appropriate flags.  Then we can delete this file.
+# TODO(rdaoud): how to cleanup the tmp test dir; "rm" here doesn't do it.
 
-syncbased -v=1 --name test/syncbased --engine memstore --v23.tcp.address 127.0.0.1:0
+testdir="$(mktemp -d "${TMPDIR:-/tmp}"/sbtest.XXXXXXXX)"
+syncbased -v=1 --name test/syncbased --engine memstore --root-dir "${testdir}" --v23.tcp.address 127.0.0.1:0