diff --git a/trefle/explorer/app.js b/trefle/explorer/app.js
index 8b13d8d4307a4878a423cc0cc73c6030d0086341..0eafd2cd39e5fe031525e421b2ce79f8ffaa18dc 100644
--- a/trefle/explorer/app.js
+++ b/trefle/explorer/app.js
@@ -15,7 +15,7 @@ function renderLabel (key, value) {
   return SCHEMA[key]['label']
 }
 
-REQUESTS = 0
+let REQUESTS = 0
 
 function request(uri, settings) {
   return new Promise( (res, rej) => {