diff --git a/src/vector/index.ts b/src/vector/index.ts
index 5b60f324c..dd182119d 100644
--- a/src/vector/index.ts
+++ b/src/vector/index.ts
@@ -77,16 +77,16 @@ function checkBrowserFeatures() {
     const featureList = Object.keys(window.Modernizr);
 
     let featureComplete = true;
-    for (let i = 0; i < featureList.length; i++) {
-        if (window.Modernizr[featureList[i]] === undefined) {
+    for (const feature of featureList) {
+        if (window.Modernizr[feature] === undefined) {
             logger.error(
                 "Looked for feature '%s' but Modernizr has no results for this. " +
-                "Has it been configured correctly?", featureList[i],
+                "Has it been configured correctly?", feature,
             );
             return false;
         }
-        if (window.Modernizr[featureList[i]] === false) {
-            logger.error("Browser missing feature: '%s'", featureList[i]);
+        if (window.Modernizr[feature] === false) {
+            logger.error("Browser missing feature: '%s'", feature);
             // toggle flag rather than return early so we log all missing features rather than just the first.
             featureComplete = false;
         }
diff --git a/src/vector/jitsi/index.ts b/src/vector/jitsi/index.ts
index b284cdcaf..4eda316ee 100644
--- a/src/vector/jitsi/index.ts
+++ b/src/vector/jitsi/index.ts
@@ -102,7 +102,7 @@ const setupCompleted = (async () => {
 
             const handleAction = (
                 action: WidgetApiAction,
-                handler: (request: IWidgetApiRequestData) => void,
+                handler: (request: IWidgetApiRequestData) => Promise<void>,
             ): void => {
                 widgetApi.on(`action:${action}`, async (ev: CustomEvent<IWidgetApiRequest>) => {
                     ev.preventDefault();