diff --git a/buildenv/jenkins/jobs/infrastructure/Update-Reference-Repos.groovy b/buildenv/jenkins/jobs/infrastructure/Update-Reference-Repos.groovy
index 5ea3a21c292..b9703c5afb1 100644
--- a/buildenv/jenkins/jobs/infrastructure/Update-Reference-Repos.groovy
+++ b/buildenv/jenkins/jobs/infrastructure/Update-Reference-Repos.groovy
@@ -173,7 +173,13 @@ timeout(time: 6, unit: 'HOURS') {
             }
         }
 
-        parallel jobs
+        if (params.PARALLEL) {
+            parallel jobs
+        } else {
+            jobs.each{ key, value ->
+                value()
+            }
+        }
     }
 }