diff --git a/src/runtime/node/buffer/index.ts b/src/runtime/node/buffer/index.ts
index 4631656..167ccae 100644
--- a/src/runtime/node/buffer/index.ts
+++ b/src/runtime/node/buffer/index.ts
@@ -22,8 +22,8 @@ export const transcode = notImplemented("buffer.transcode");
 export const isUtf8 = notImplemented("buffer.isUtf8");
 export const isAscii = notImplemented("buffer.isAscii");
 
-export const btoa = global.btoa;
-export const atob = globalThis.atob;
+export const btoa = globalThis.btoa.bind(globalThis);
+export const atob = globalThis.atob.bind(globalThis);
 
 export const kStringMaxLength = 0; // TODO
 export const constants = {
diff --git a/test/workerd/tests.mjs b/test/workerd/tests.mjs
index 0933975..fdee1dc 100644
--- a/test/workerd/tests.mjs
+++ b/test/workerd/tests.mjs
@@ -40,8 +40,8 @@ export const unenv_polyfills_buffer = {
     const Buffer = buffer.Buffer;
     assert.strictEqual(typeof buffer.isAscii, "function");
     assert.strictEqual(typeof buffer.isUtf8, "function");
-    //assert.strictEqual(buffer.btoa("hello"), "aGVsbG8=");
-    //assert.strictEqual(buffer.atob("aGVsbG8="), "hello");
+    assert.strictEqual(buffer.btoa("hello"), "aGVsbG8=");
+    assert.strictEqual(buffer.atob("aGVsbG8="), "hello");
     assert.strictEqual(typeof buffer.transcode, "function");
     assert.strictEqual(typeof buffer.File, "function");
     assert.strictEqual(typeof buffer.Blob, "function");