diff --git a/packages/encoding/src/utf8.ts b/packages/encoding/src/utf8.ts
index a23b0091..79380bba 100644
--- a/packages/encoding/src/utf8.ts
+++ b/packages/encoding/src/utf8.ts
@@ -1,38 +1,17 @@
-// Global symbols in some environments
+/* eslint-disable @typescript-eslint/naming-convention */
+// Global symbols in both browsers and Node.js since v11
 // https://developer.mozilla.org/en-US/docs/Web/API/TextEncoder
 // https://developer.mozilla.org/en-US/docs/Web/API/TextDecoder
-/* eslint-disable-next-line @typescript-eslint/naming-convention */
-declare const TextEncoder: any | undefined;
-/* eslint-disable-next-line @typescript-eslint/naming-convention */
-declare const TextDecoder: any | undefined;
-
-function isValidUtf8(data: Uint8Array): boolean {
-  const toStringAndBack = Buffer.from(Buffer.from(data).toString("utf8"), "utf8");
-  return Buffer.compare(Buffer.from(data), toStringAndBack) === 0;
-}
+// https://nodejs.org/docs/latest-v12.x/api/util.html#util_class_util_textencoder
+// https://nodejs.org/docs/latest-v12.x/api/util.html#util_class_util_textdecoder
+// See https://github.com/microsoft/TypeScript/issues/31535
+declare const TextEncoder: any;
+declare const TextDecoder: any;
 
 export function toUtf8(str: string): Uint8Array {
-  // Browser and future nodejs (https://github.com/nodejs/node/issues/20365)
-  if (typeof TextEncoder !== "undefined") {
-    return new TextEncoder().encode(str);
-  }
-
-  // Use Buffer hack instead of nodejs util.TextEncoder to ensure
-  // webpack does not bundle the util module for browsers.
-  return new Uint8Array(Buffer.from(str, "utf8"));
+  return new TextEncoder().encode(str);
 }
 
 export function fromUtf8(data: Uint8Array): string {
-  // Browser and future nodejs (https://github.com/nodejs/node/issues/20365)
-  if (typeof TextDecoder !== "undefined") {
-    return new TextDecoder("utf-8", { fatal: true }).decode(data);
-  }
-
-  // Use Buffer hack instead of nodejs util.TextDecoder to ensure
-  // webpack does not bundle the util module for browsers.
-  // Buffer.toString has no fatal option
-  if (!isValidUtf8(data)) {
-    throw new Error("Invalid UTF8 data");
-  }
-  return Buffer.from(data).toString("utf8");
+  return new TextDecoder("utf-8", { fatal: true }).decode(data);
 }