diff --git a/vc-utils/keymanager.sh b/vc-utils/keymanager.sh
index 4c00e301..bd642b5f 100755
--- a/vc-utils/keymanager.sh
+++ b/vc-utils/keymanager.sh
@@ -242,7 +242,7 @@ exit-sign() {
         *) echo "Unexpected return code $__code. Result: $__result"; exit 1;;
     esac
     # This is only reached for 200
-    if [[ ${__result} == '{"data":'* ]]; then
+    if jq -e '.data != null' <<< "${__result}" &>/dev/null; then
         __result=$(echo "${__result}" | jq -c '.data')
     fi