diff --git a/src/server.js b/src/server.js
index 71c7c4f..96bcac8 100644
--- a/src/server.js
+++ b/src/server.js
@@ -212,7 +212,7 @@ function start(opts) {
                 StyleSourceId;
               if (isValidHttpUrl(StyleSourceId)) {
                 id =
-                  id.replace(/^.*\/(.*)$/, '$1') + '_' + fnv1a(StyleSourceId);
+                fnv1a(StyleSourceId) + '_' + id.replace(/^.*\/(.*)$/, '$1');
               }
               while (data[id]) id += '_'; //if the data source id already exists, add a "_" untill it doesn't
               //Add the new data source to the data array.