diff --git a/lib/buffer.js b/lib/buffer.js
index e41e3662662609..12f40693400c02 100644
--- a/lib/buffer.js
+++ b/lib/buffer.js
@@ -30,9 +30,13 @@ binding.setupBufferJS(Buffer.prototype, bindingObj);
 const zeroFill = bindingObj.zeroFill || [0];
 
 function createUnsafeBuffer(size) {
+  return new FastBuffer(createUnsafeArrayBuffer(size));
+}
+
+function createUnsafeArrayBuffer(size) {
   zeroFill[0] = 0;
   try {
-    return new FastBuffer(size);
+    return new ArrayBuffer(size);
   } finally {
     zeroFill[0] = 1;
   }
@@ -40,7 +44,7 @@ function createUnsafeBuffer(size) {
 
 function createPool() {
   poolSize = Buffer.poolSize;
-  allocPool = createUnsafeBuffer(poolSize);
+  allocPool = createUnsafeArrayBuffer(poolSize);
   poolOffset = 0;
 }
 createPool();
@@ -183,7 +187,7 @@ function allocate(size) {
   if (size < (Buffer.poolSize >>> 1)) {
     if (size > (poolSize - poolOffset))
       createPool();
-    var b = allocPool.slice(poolOffset, poolOffset + size);
+    var b = new FastBuffer(allocPool, poolOffset, size);
     poolOffset += size;
     alignPool();
     return b;
@@ -210,8 +214,12 @@ function fromString(string, encoding) {
 
   if (length > (poolSize - poolOffset))
     createPool();
-  var actual = allocPool.write(string, poolOffset, encoding);
-  var b = allocPool.slice(poolOffset, poolOffset + actual);
+  var b = new FastBuffer(allocPool, poolOffset, length);
+  var actual = b.write(string, encoding);
+  if (actual !== length) {
+    // byteLength() may overestimate. That’s a rare case, though.
+    b = new FastBuffer(allocPool, poolOffset, actual);
+  }
   poolOffset += actual;
   alignPool();
   return b;