diff --git a/cascading-pr.sh b/cascading-pr.sh
index bf91efe..d45c9df 100755
--- a/cascading-pr.sh
+++ b/cascading-pr.sh
@@ -235,11 +235,11 @@ function wait_destination_ci() {
 
 function upsert_fork() {
     if repo_curl ${options[destination_repo]} api_json ${options[destination_fork_api]} > $TMPDIR/fork.json 2> /dev/null ; then
-	if test "$(jq --raw-output .fork)" != true ; then
+	if test "$(jq --raw-output .fork < $TMPDIR/fork.json)" != true ; then
 	    log_error "the destination fork already exists but is not a fork ${options[destination_fork]}"
 	    return 1
 	fi
-	local forked_from_repo=$(jq --raw-output .parent.full_name)
+	local forked_from_repo=$(jq --raw-output .parent.full_name < $TMPDIR/fork.json)
 	if test "$forked_from_repo" != "${options[destination_repo]}" ; then
 	    log_error "${options[destination_fork]} must be a fork of ${options[destination_repo]} but is a fork of $forked_from_repo instead"
 	    return 1