diff --git a/molecules-and-light_en.html b/molecules-and-light_en.html
index 6735692..77b400c 100644
--- a/molecules-and-light_en.html
+++ b/molecules-and-light_en.html
@@ -44,6 +44,10 @@
           "phet-io",
           "adapted-from-phet"
         ],
+        "preload": [
+          "../sherpa/lib/fluent-0.13.0.min.js",
+          "../chipper/js/load-unbuilt-fluent-strings.js"
+        ],
         "simFeatures": {
           "supportsSound": true,
           "supportsInteractiveDescription": true
@@ -110,7 +114,9 @@
     '../sherpa/lib/seedrandom-2.4.2.js',
     '../sherpa/lib/base64-js-1.2.0.js',
     '../sherpa/lib/TextEncoderLite-3c9f6f0.js',
-    '../tandem/js/PhetioIDUtils.js'
+    '../tandem/js/PhetioIDUtils.js',
+    '../sherpa/lib/fluent-0.13.0.min.js',
+    '../chipper/js/load-unbuilt-fluent-strings.js'
   ];
 
   if ( brand === 'phet-io' ) {
diff --git a/package.json b/package.json
index 5cb6961..721814d 100644
--- a/package.json
+++ b/package.json
@@ -21,6 +21,10 @@
       "phet-io",
       "adapted-from-phet"
     ],
+    "preload": [
+      "../sherpa/lib/fluent-0.13.0.min.js",
+      "../chipper/js/load-unbuilt-fluent-strings.js"
+    ],
     "simFeatures": {
       "supportsSound": true,
       "supportsInteractiveDescription": true