diff --git a/docker/start-soda.sh b/docker/start-soda.sh
index d6170d2d5b0bc1839c0b57950aa6e9e6ee88afa7..a14ca3aef56037f777d7b523ba785c093b0ab954 100755
--- a/docker/start-soda.sh
+++ b/docker/start-soda.sh
@@ -6,9 +6,11 @@ set -eux
 date
 env
 
-# set optional
+# set optional to defaults if:
+# :- var not exist or is empty string/null
+# -  var not exist
 ENABLE_ASYNC_UWS=${ENABLE_ASYNC_UWS:-}
-ACCESS_CONTEXT_ROOT=${ACCESS_CONTEXT_ROOT:-soda}
+ACCESS_CONTEXT_ROOT=${ACCESS_CONTEXT_ROOT-soda}
 
 OIDC_RAP_URL=${OIDC_RAP_URL:-}
 OIDC_GMS_URL=${OIDC_GMS_URL:-}