diff --git a/types/text-encoding/index.d.ts b/types/text-encoding/index.d.ts
index 08536c5981..50788db138 100644
--- a/types/text-encoding/index.d.ts
+++ b/types/text-encoding/index.d.ts
@@ -21,7 +21,7 @@ declare namespace TextEncoding {
         encoding: string;
         fatal: boolean;
         ignoreBOM: boolean;
-        decode(input?: ArrayBufferView, options?: TextDecodeOptions): string;
+        decode(input?: ArrayBuffer | ArrayBufferView, options?: TextDecodeOptions): string;
     }
 
     interface TextEncoder {
diff --git a/types/text-encoding/text-encoding-tests.ts b/types/text-encoding/text-encoding-tests.ts
index f92e1f4bca..914f680bd3 100644
--- a/types/text-encoding/text-encoding-tests.ts
+++ b/types/text-encoding/text-encoding-tests.ts
@@ -27,6 +27,7 @@ function test_encoder() {
 function test_decoder() {
     var text = "plain text";
     var uint8array: Uint8Array = TextEncoder().encode(text);
+    var arrayBuffer: ArrayBuffer = uint8array.buffer
 
     // constructor
     text = new TextDecoder().decode(uint8array);
@@ -56,5 +57,6 @@ function test_decoder() {
     // methods
     decoder.decode();
     decoder.decode(uint8array);
+    decoder.decode(arrayBuffer);
     decoder.decode(uint8array, { stream: true });
-}
\ No newline at end of file
+}