diff --git a/hack/jenkins/upload-to-gcs.sh b/hack/jenkins/upload-to-gcs.sh
index 37cb85018fd..81d805c8fe2 100755
--- a/hack/jenkins/upload-to-gcs.sh
+++ b/hack/jenkins/upload-to-gcs.sh
@@ -151,15 +151,24 @@ function update_job_result_cache() {
 
   mkdir -p ${tmp_results%/*}
 
+  # Construct a valid json file
+  echo "[" > ${tmp_results}
+
   for upload_attempt in $(seq 3); do
     echo "Copying ${job_results} to ${tmp_results} (attempt ${upload_attempt})"
-    gsutil -q cp ${job_results} ${tmp_results} 2>&- || continue
+    gsutil -q cat ${job_results} 2>&- |\
+     sed -n 's/^\({"version".*}\),*/\1,/p' >> ${tmp_results} || continue
+
     break
   done
 
   echo "{\"version\": \"${version}\", \"buildnumber\": \"${BUILD_NUMBER}\"," \
        "\"result\": \"${build_result}\"}" >> ${tmp_results}
 
+  # JSON doesn't like terminating elements to contain a "," separator, so
+  # terminate the elements with an empty one.
+  echo -e "{}\n]" >> ${tmp_results}
+
   for upload_attempt in $(seq 3); do
     echo "Copying ${tmp_results} to ${job_results} (attempt ${upload_attempt})"
     gsutil -q -h "Content-Type:application/json" cp -a "${gcs_acl}" \