diff --git a/lib/update.js b/lib/update.js
index 507bff9..72c85c9 100644
--- a/lib/update.js
+++ b/lib/update.js
@@ -1,8 +1,10 @@
 import wrap from './wrap';
-import isEmpty from './util/isEmpty';
-import defaultObject from './util/defaultObject';
 import isPlainObject from 'lodash/lang/isPlainObject';
 
+function isEmpty(object) {
+  return !Object.keys(object).length;
+}
+
 function reduce(object, callback, initialValue) {
   return Object.keys(object).reduce((acc, key) => {
     return callback(acc, object[key], key);
@@ -63,7 +65,9 @@ function update(updates, object, ...args) {
     return updates;
   }
 
-  const defaultedObject = defaultObject(object, updates);
+  const defaultedObject = (typeof object === 'undefined' || object === null) ?
+    {} :
+    object;
 
   const resolvedUpdates = resolveUpdates(updates, defaultedObject);
 
diff --git a/lib/util/defaultObject.js b/lib/util/defaultObject.js
deleted file mode 100644
index be6286f..0000000
--- a/lib/util/defaultObject.js
+++ /dev/null
@@ -1,35 +0,0 @@
-import isEmpty from './isEmpty';
-
-function isInt(value) {
-  if (isNaN(value)) {
-    return false;
-  }
-  const x = parseFloat(value);
-  return (x | 0) === x;
-}
-
-function isArrayUpdate(updates) {
-  for (const updateKey of Object.keys(updates)) {
-    if (!isInt(updateKey)) { return false; }
-  }
-
-  return true;
-}
-
-function arrayOrObject(updates) {
-  if (!isEmpty(updates) && isArrayUpdate(updates)) {
-    return [];
-  }
-
-  return {};
-}
-
-function defaultObject(object, updates) {
-  if (typeof object === 'undefined' || object === null) {
-    return arrayOrObject(updates);
-  }
-
-  return object;
-}
-
-export default defaultObject;
diff --git a/lib/util/isEmpty.js b/lib/util/isEmpty.js
deleted file mode 100644
index 4e27ba2..0000000
--- a/lib/util/isEmpty.js
+++ /dev/null
@@ -1,5 +0,0 @@
-function isEmpty(object) {
-  return !Object.keys(object).length;
-}
-
-export default isEmpty;
diff --git a/test/updateIn-spec.js b/test/updateIn-spec.js
index b7c9cc4..a89ca97 100644
--- a/test/updateIn-spec.js
+++ b/test/updateIn-spec.js
@@ -27,12 +27,6 @@ describe('u.updateIn', () => {
     expect(result).to.eql({ a: [0, 3, 0] });
   });
 
-  it('can create array if all keys are numbers', () => {
-    const result = u.updateIn('a.0', 3, null);
-
-    expect(result).to.eql({ a: [3] });
-  });
-
   it('can be partially applied', () => {
     const object = { a: { b: 0 } };
     const result = u.updateIn('a.b')(3)(object);
diff --git a/test/updeep-spec.js b/test/updeep-spec.js
index 17ece4b..22ea60f 100644
--- a/test/updeep-spec.js
+++ b/test/updeep-spec.js
@@ -42,18 +42,6 @@ describe('updeep', () => {
     expect(u(null, {})).to.be.null;
   });
 
-  it('can create array if all keys are numbers', () => {
-    const result = u({ 0: 'hi', '1': 'world' }, null);
-
-    expect(result).to.eql(['hi', 'world']);
-  });
-
-  it('does not create array if any key is not number', () => {
-    const result = u({ 0: 'hi', '1a': 'world' }, null);
-
-    expect(result).to.eql({ 0: 'hi', '1a': 'world' });
-  });
-
   it('can add an element to an array', () => {
     const object = [];
     const result = u({ 0: 3 }, object);