diff --git a/src/index.ts b/src/index.ts
index 5c33ddd..ca5a446 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -41,7 +41,7 @@ function getButtons(toolbar: Element): HTMLElement[] {
   return els
 }
 
-function keydown(fn: (arg0: KeyboardEvent) => void): (arg0: KeyboardEvent) => void {
+function keydown(fn: (event: KeyboardEvent) => void): (event: KeyboardEvent) => void {
   return function (event: KeyboardEvent) {
     if (event.key === ' ' || event.key === 'Enter') {
       event.preventDefault()
diff --git a/tsconfig.json b/tsconfig.json
index 89916cf..f749792 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -1,6 +1,6 @@
 {
   "compilerOptions": {
-    "module": "esnext",
+    "module": "es2020",
     "target": "es2017",
     "strict": true,
     "declaration": true,