diff --git a/README.md b/README.md
index 1e1f0d429299c05a37bce6d17b1bd831d433c2c5..e269403fff6a52519cdc5cf4b8c48ec6b47da23c 100644
--- a/README.md
+++ b/README.md
@@ -38,8 +38,8 @@ Configuration parameters are set by these docker environment variables:
 | **DB_USERNAME** | DB user which has access to ObsTAP |
 | **DB_PASSWORD** | and user's password |
 | *optional:* |  |
-| **CUTOUT_SERVICE_URL** | URL in Service Descriptor of the VOTable response |
-| **DISCOVERY_CONTEXT_ROOT** | root of the end-points |
+| **CUTOUT_SERVICE_URL** | URL in Service Descriptor of the VOTable response (default: <empty>)|
+| **DISCOVERY_CONTEXT_ROOT** | root of the end-points (default: siav2) |
 
 
 ## vlkb-obscore
diff --git a/docker/start-siav2.sh b/docker/start-siav2.sh
index 200a1478a7377ab90eaecda1c16bc3d4feb9494d..5d45c9bb802403a18ed248815d024c9a8470705c 100755
--- a/docker/start-siav2.sh
+++ b/docker/start-siav2.sh
@@ -7,6 +7,7 @@ date
 env
 
 # set optional
+CUTOUT_SERVICE_URL=${CUTOUT_SERVICE_URL:-""}
 DISCOVERY_CONTEXT_ROOT=${DISCOVERY_CONTEXT_ROOT:-siav2}
 DBG_LEVEL=${DEBUG_LEVEL:-CONFIG}