diff --git a/src/object/object.util.test.ts b/src/object/object.util.test.ts
index 126cbe6c..b16efd96 100644
--- a/src/object/object.util.test.ts
+++ b/src/object/object.util.test.ts
@@ -22,7 +22,9 @@ import {
   _objectAssignExact,
   _objectNullValuesToUndefined,
   _omit,
+  _omitWithUndefined,
   _pick,
+  _pickWithUndefined,
   _set,
   _unset,
 } from './object.util'
@@ -42,7 +44,6 @@ test('_pick', () => {
 
   const fields = ['a', 'c', 'd', 'e'] as const
   const r = f(obj, fields as any)
-  // console.log(r)
   expect(r).toEqual({ a: 1, c: 3, d: false })
   expect('e' in r).toBe(false) // should not add more fields with 'undefined' value
   // should not mutate
@@ -57,6 +58,43 @@ test('_pick', () => {
   expect(obj2).toBe(obj)
 })
 
+test('_pickWithUndefined', () => {
+  const f = _pickWithUndefined
+
+  const obj = {
+    a: 1,
+    b: 2,
+    c: 3,
+    d: false,
+  }
+
+  // empty fields
+  expect(f(obj, [])).toEqual({
+    a: undefined,
+    b: undefined,
+    c: undefined,
+    d: undefined,
+  })
+
+  const fields = ['a', 'c', 'd', 'e'] as const
+  const r = f(obj, fields as any)
+  expect(r).toEqual({ a: 1, b: undefined, c: 3, d: false })
+  expect('e' in r).toBe(false) // should not add more fields with 'undefined' value
+  // should not mutate
+  expect(obj.c).toBe(3)
+  expect(r).not.toBe(obj)
+
+  // should mutate
+  const obj2 = f(obj, ['a'], true)
+  expect(obj2).toEqual({
+    a: 1,
+    b: undefined,
+    c: undefined,
+    d: undefined,
+  })
+  expect(obj2).toBe(obj)
+})
+
 test('_omit', () => {
   const obj = {
     a: 1,
@@ -68,8 +106,6 @@ test('_omit', () => {
 
   _deepFreeze(obj)
 
-  // expect(_omit(obj)).toEqual(obj)
-
   // empty props
   expect(_omit(obj, [])).toEqual(obj)
 
@@ -85,6 +121,37 @@ test('_omit', () => {
   })
 })
 
+test('_omitWithUndefined', () => {
+  const obj = {
+    a: 1,
+    b: 2,
+    c: 3,
+    d: false,
+    e: undefined,
+  }
+
+  _deepFreeze(obj)
+
+  // empty props
+  expect(_omitWithUndefined(obj, [])).toEqual(obj)
+
+  expect(_omitWithUndefined(obj, ['b', 'c'])).toEqual({
+    a: 1,
+    b: undefined,
+    c: undefined,
+    d: false,
+    e: undefined,
+  })
+
+  expect(_omit(obj, ['a', 'd', 'e'])).toEqual({
+    a: undefined,
+    b: 2,
+    c: 3,
+    d: undefined,
+    e: undefined,
+  })
+})
+
 test('_omit mutate', () => {
   const obj = {
     a: 1,
@@ -103,6 +170,26 @@ test('_omit mutate', () => {
   expect(obj2).toBe(obj)
 })
 
+test('_omitWithUndefined mutating', () => {
+  const obj = {
+    a: 1,
+    b: 2,
+    c: 3,
+    d: false,
+    e: undefined,
+  }
+
+  const obj2 = _omitWithUndefined(obj, ['b', 'c'], true)
+  expect(obj2).toEqual({
+    a: 1,
+    b: undefined,
+    c: undefined,
+    d: false,
+    e: undefined,
+  })
+  expect(obj2).toBe(obj)
+})
+
 test('_mask', () => {
   const o = {
     a: '1',
diff --git a/src/object/object.util.ts b/src/object/object.util.ts
index 2d64f48f..73879890 100644
--- a/src/object/object.util.ts
+++ b/src/object/object.util.ts
@@ -21,15 +21,33 @@ export function _pick<T extends AnyObject, K extends keyof T>(
 ): T {
   if (mutate) {
     // Start as original object (mutable), DELETE properties that are not whitelisted
-    for (const prop of Object.keys(obj)) {
-      if (!props.includes(prop as K)) delete obj[prop]
+    for (const k of Object.keys(obj)) {
+      if (!props.includes(k as K)) delete obj[k]
     }
     return obj
   }
   // Start as empty object, pick/add needed properties
   const r = {} as T
-  for (const prop of props) {
-    if (prop in obj) r[prop] = obj[prop]
+  for (const k of props) {
+    if (k in obj) r[k] = obj[k]
+  }
+  return r
+}
+
+/**
+ * Sets all properties of an object except passed ones to `undefined`.
+ * This is a more performant alternative to `_pick` that does picking/deleting.
+ */
+export function _pickWithUndefined<T extends AnyObject, K extends keyof T>(
+  obj: T,
+  props: readonly K[],
+  mutate = false,
+): T {
+  const r: T = mutate ? obj : { ...obj }
+  for (const k of Object.keys(r)) {
+    if (!props.includes(k as K)) {
+      r[k as K] = undefined as any
+    }
   }
   return r
 }
@@ -44,15 +62,31 @@ export function _omit<T extends AnyObject, K extends keyof T>(
   mutate = false,
 ): T {
   if (mutate) {
-    for (const prop of props) {
-      delete obj[prop]
+    for (const k of props) {
+      delete obj[k]
     }
     return obj
   }
 
   const r = {} as T
-  for (const prop of Object.keys(obj)) {
-    if (!props.includes(prop as K)) r[prop as K] = obj[prop]
+  for (const k of Object.keys(obj)) {
+    if (!props.includes(k as K)) r[k as K] = obj[k]
+  }
+  return r
+}
+
+/**
+ * Sets all passed properties of an object to `undefined`.
+ * This is a more performant alternative to `_omit` that does picking/deleting.
+ */
+export function _omitWithUndefined<T extends AnyObject, K extends keyof T>(
+  obj: T,
+  props: readonly K[],
+  mutate = false,
+): T {
+  const r: T = mutate ? obj : { ...obj }
+  for (const k of props) {
+    r[k] = undefined as any
   }
   return r
 }
@@ -67,8 +101,8 @@ export function _omit<T extends AnyObject, K extends keyof T>(
  */
 export function _mask<T extends AnyObject>(obj: T, props: string[], mutate = false): T {
   const r = mutate ? obj : _deepCopy(obj)
-  for (const prop of props) {
-    _unset(r, prop)
+  for (const k of props) {
+    _unset(r, k)
   }
   return r
 }
diff --git a/src/object/sortObject.ts b/src/object/sortObject.ts
index f3a7cbb6..06c4dde7 100644
--- a/src/object/sortObject.ts
+++ b/src/object/sortObject.ts
@@ -1,5 +1,4 @@
 import type { AnyObject } from '../index'
-import { _omit } from '../index'
 
 /**
  * Returns new object with keys sorder in the given order.
@@ -9,15 +8,18 @@ import { _omit } from '../index'
 export function _sortObject<T extends AnyObject>(obj: T, keyOrder: (keyof T)[]): T {
   const r = {} as T
 
-  keyOrder.forEach(key => {
-    if (key in obj) {
-      r[key] = obj[key]
+  // First, go over ordered keys
+  for (const k of keyOrder) {
+    if (k in obj) {
+      r[k] = obj[k]
     }
-  })
+  }
 
-  Object.entries(_omit(obj, keyOrder)).forEach(([k, v]) => {
+  // Second, go over all other keys
+  for (const [k, v] of Object.entries(obj)) {
+    if (keyOrder.includes(k)) continue
     r[k as keyof T] = v
-  })
+  }
 
   return r
 }
diff --git a/src/object/sortObjectDeep.ts b/src/object/sortObjectDeep.ts
index 13cb7021..f7eeea79 100644
--- a/src/object/sortObjectDeep.ts
+++ b/src/object/sortObjectDeep.ts
@@ -1,5 +1,3 @@
-import { _isObject } from '..'
-
 /**
  * based on: https://github.com/IndigoUnited/js-deep-sort-object
  */
@@ -9,16 +7,12 @@ export function _sortObjectDeep<T>(o: T): T {
     return o.map(_sortObjectDeep) as any
   }
 
-  if (_isObject(o)) {
-    const out = {} as T
-
-    Object.keys(o)
-      .sort((a, b) => a.localeCompare(b))
-      .forEach(k => {
-        out[k as keyof T] = _sortObjectDeep(o[k as keyof T])
-      })
-
-    return out
+  if (o && typeof o === 'object') {
+    const r = {} as T
+    for (const k of Object.keys(o).sort((a, b) => a.localeCompare(b)) as (keyof T)[]) {
+      r[k] = _sortObjectDeep(o[k])
+    }
+    return r
   }
 
   return o