diff --git a/js/perf/core.js b/js/perf/core.js
index 091a86a0f..04ea3c49f 100644
--- a/js/perf/core.js
+++ b/js/perf/core.js
@@ -10,7 +10,7 @@ const Scripting = imports.ui.scripting;
 // someone should be able to get an idea of how well the shell is performing
 // on a particular system.
 
-let METRICS = {
+var METRICS = {
     overviewLatencyFirst:
     { description: "Time to first frame after triggering overview, first time",
       units: "us" },
diff --git a/js/perf/hwtest.js b/js/perf/hwtest.js
index d5b417da3..31a25a715 100644
--- a/js/perf/hwtest.js
+++ b/js/perf/hwtest.js
@@ -2,7 +2,7 @@ const { Clutter, Gio, Gtk, Shell } = imports.gi;
 const Main = imports.ui.main;
 const Scripting = imports.ui.scripting;
 
-let METRICS = {
+var METRICS = {
     timeToDesktop:
     { description: "Time from starting graphical.target to desktop showing",
       units: "us" },