diff --git a/lib/utils/text-utils.js b/lib/utils/text-utils.js
--- a/lib/utils/text-utils.js
+++ b/lib/utils/text-utils.js
@@ -14,7 +14,7 @@
 
   const comma = maxNumberOfNouns > 2 && nouns.length > 2 ? ',' : '';
   if (nouns.length <= maxNumberOfNouns) {
-    const prefix = nouns.slice(0, nouns.length - 1).join(', ');
+    const prefix = nouns.slice(0, -1).join(', ');
     return `${prefix}${comma} and ${nouns[nouns.length - 1]}`;
   } else {
     const prefix = nouns.slice(0, maxNumberOfNouns - 1).join(', ');
diff --git a/web/modals/modal-provider.react.js b/web/modals/modal-provider.react.js
--- a/web/modals/modal-provider.react.js
+++ b/web/modals/modal-provider.react.js
@@ -30,7 +30,7 @@
     $ReadOnlyArray<[React.Node, string]>,
   >([]);
   const popModal = React.useCallback(
-    () => setModals(oldModals => oldModals.slice(0, oldModals.length - 1)),
+    () => setModals(oldModals => oldModals.slice(0, -1)),
     [],
   );
   const pushModal = React.useCallback(newModal => {