diff --git a/_baseDifference.js b/_baseDifference.js
index 0fe5d64c2..be119496a 100644
--- a/_baseDifference.js
+++ b/_baseDifference.js
@@ -2,7 +2,6 @@ import SetCache from './_SetCache.js';
 import arrayIncludes from './_arrayIncludes.js';
 import arrayIncludesWith from './_arrayIncludesWith.js';
 import arrayMap from './_arrayMap.js';
-import baseUnary from './_baseUnary.js';
 import cacheHas from './_cacheHas.js';
 
 /** Used as the size to enable large array optimizations. */
@@ -31,7 +30,7 @@ function baseDifference(array, values, iteratee, comparator) {
     return result;
   }
   if (iteratee) {
-    values = arrayMap(values, baseUnary(iteratee));
+    values = arrayMap(values, value => iteratee(value));
   }
   if (comparator) {
     includes = arrayIncludesWith;
diff --git a/_baseIntersection.js b/_baseIntersection.js
index ef55ef34f..7935b4d99 100644
--- a/_baseIntersection.js
+++ b/_baseIntersection.js
@@ -2,7 +2,6 @@ import SetCache from './_SetCache.js';
 import arrayIncludes from './_arrayIncludes.js';
 import arrayIncludesWith from './_arrayIncludesWith.js';
 import arrayMap from './_arrayMap.js';
-import baseUnary from './_baseUnary.js';
 import cacheHas from './_cacheHas.js';
 
 /* Built-in method references for those with the same name as other `lodash` methods. */
@@ -32,7 +31,7 @@ function baseIntersection(arrays, iteratee, comparator) {
   while (othIndex--) {
     array = arrays[othIndex];
     if (othIndex && iteratee) {
-      array = arrayMap(array, baseUnary(iteratee));
+      array = arrayMap(array, valye => iteratee(value));
     }
     maxLength = nativeMin(array.length, maxLength);
     caches[othIndex] = !comparator && (iteratee || (length >= 120 && array.length >= 120))
diff --git a/_baseOrderBy.js b/_baseOrderBy.js
index 641599472..147612a82 100644
--- a/_baseOrderBy.js
+++ b/_baseOrderBy.js
@@ -2,7 +2,6 @@ import arrayMap from './_arrayMap.js';
 import baseIteratee from './_baseIteratee.js';
 import baseMap from './_baseMap.js';
 import baseSortBy from './_baseSortBy.js';
-import baseUnary from './_baseUnary.js';
 import compareMultiple from './_compareMultiple.js';
 import identity from './identity.js';
 
@@ -17,7 +16,7 @@ import identity from './identity.js';
  */
 function baseOrderBy(collection, iteratees, orders) {
   let index = -1;
-  iteratees = arrayMap(iteratees.length ? iteratees : [identity], baseUnary(baseIteratee));
+  iteratees = arrayMap(iteratees.length ? iteratees : [identity], value => baseIteratee(value));
 
   const result = baseMap(collection, (value, key, collection) => {
     const criteria = arrayMap(iteratees, iteratee => iteratee(value));
diff --git a/_basePullAll.js b/_basePullAll.js
index e292b2fa9..19784a9c1 100644
--- a/_basePullAll.js
+++ b/_basePullAll.js
@@ -1,7 +1,6 @@
 import arrayMap from './_arrayMap.js';
 import baseIndexOf from './_baseIndexOf.js';
 import baseIndexOfWith from './_baseIndexOfWith.js';
-import baseUnary from './_baseUnary.js';
 import copyArray from './_copyArray.js';
 
 /** Used for built-in method references. */
@@ -32,7 +31,7 @@ function basePullAll(array, values, iteratee, comparator) {
     values = copyArray(values);
   }
   if (iteratee) {
-    seen = arrayMap(array, baseUnary(iteratee));
+    seen = arrayMap(array, value => iteratee(value));
   }
   while (++index < length) {
     let fromIndex = 0;
diff --git a/_baseUnary.js b/_baseUnary.js
deleted file mode 100644
index 039390289..000000000
--- a/_baseUnary.js
+++ /dev/null
@@ -1,12 +0,0 @@
-/**
- * The base implementation of `_.unary` without support for storing metadata.
- *
- * @private
- * @param {Function} func The function to cap arguments for.
- * @returns {Function} Returns the new capped function.
- */
-function baseUnary(func) {
-  return value => func(value);
-}
-
-export default baseUnary;
diff --git a/_createOver.js b/_createOver.js
index 1e60bea8e..ae55b3a0b 100644
--- a/_createOver.js
+++ b/_createOver.js
@@ -1,7 +1,6 @@
 import apply from './_apply.js';
 import arrayMap from './_arrayMap.js';
 import baseIteratee from './_baseIteratee.js';
-import baseUnary from './_baseUnary.js';
 
 /**
  * Creates a function like `_.over`.
@@ -12,7 +11,7 @@ import baseUnary from './_baseUnary.js';
  */
 function createOver(arrayFunc) {
   return (...iteratees) => {
-    iteratees = arrayMap(iteratees, baseUnary(baseIteratee));
+    iteratees = arrayMap(iteratees, iteratee => baseIteratee(iteratee));
     return (...args) => {
       const thisArg = this;
       return arrayFunc(iteratees, iteratee => apply(iteratee, thisArg, args));
diff --git a/isArrayBuffer.js b/isArrayBuffer.js
index 7a9b46772..93887450d 100644
--- a/isArrayBuffer.js
+++ b/isArrayBuffer.js
@@ -1,5 +1,4 @@
 import baseIsArrayBuffer from './_baseIsArrayBuffer.js';
-import baseUnary from './_baseUnary.js';
 import nodeUtil from './_nodeUtil.js';
 
 /* Node.js helper references. */
@@ -22,6 +21,8 @@ const nodeIsArrayBuffer = nodeUtil && nodeUtil.isArrayBuffer;
  * _.isArrayBuffer(new Array(2));
  * // => false
  */
-const isArrayBuffer = nodeIsArrayBuffer ? baseUnary(nodeIsArrayBuffer) : baseIsArrayBuffer;
+const isArrayBuffer = nodeIsArrayBuffer
+  ? value => nodeIsArrayBuffer(value)
+  : baseIsArrayBuffer;
 
 export default isArrayBuffer;
diff --git a/isDate.js b/isDate.js
index 3fffa3f16..4c28e1254 100644
--- a/isDate.js
+++ b/isDate.js
@@ -1,5 +1,4 @@
 import baseIsDate from './_baseIsDate.js';
-import baseUnary from './_baseUnary.js';
 import nodeUtil from './_nodeUtil.js';
 
 /* Node.js helper references. */
@@ -22,6 +21,8 @@ const nodeIsDate = nodeUtil && nodeUtil.isDate;
  * _.isDate('Mon April 23 2012');
  * // => false
  */
-const isDate = nodeIsDate ? baseUnary(nodeIsDate) : baseIsDate;
+const isDate = nodeIsDate
+  ? value => nodeIsDate(value)
+  : baseIsDate;
 
 export default isDate;
diff --git a/isMap.js b/isMap.js
index 277bc7bb9..d1192ffd6 100644
--- a/isMap.js
+++ b/isMap.js
@@ -1,5 +1,4 @@
 import baseIsMap from './_baseIsMap.js';
-import baseUnary from './_baseUnary.js';
 import nodeUtil from './_nodeUtil.js';
 
 /* Node.js helper references. */
@@ -22,6 +21,8 @@ const nodeIsMap = nodeUtil && nodeUtil.isMap;
  * _.isMap(new WeakMap);
  * // => false
  */
-const isMap = nodeIsMap ? baseUnary(nodeIsMap) : baseIsMap;
+const isMap = nodeIsMap
+  ? value => nodeIsMap(value)
+  : baseIsMap;
 
 export default isMap;
diff --git a/isRegExp.js b/isRegExp.js
index 7282f1e7c..d4b9aba2d 100644
--- a/isRegExp.js
+++ b/isRegExp.js
@@ -1,5 +1,4 @@
 import baseIsRegExp from './_baseIsRegExp.js';
-import baseUnary from './_baseUnary.js';
 import nodeUtil from './_nodeUtil.js';
 
 /* Node.js helper references. */
@@ -22,6 +21,8 @@ const nodeIsRegExp = nodeUtil && nodeUtil.isRegExp;
  * _.isRegExp('/abc/');
  * // => false
  */
-const isRegExp = nodeIsRegExp ? baseUnary(nodeIsRegExp) : baseIsRegExp;
+const isRegExp = nodeIsRegExp
+  ? value => nodeIsRegExp(value)
+  : baseIsRegExp;
 
 export default isRegExp;
diff --git a/isSet.js b/isSet.js
index 56475bd41..83ed191a5 100644
--- a/isSet.js
+++ b/isSet.js
@@ -1,5 +1,4 @@
 import baseIsSet from './_baseIsSet.js';
-import baseUnary from './_baseUnary.js';
 import nodeUtil from './_nodeUtil.js';
 
 /* Node.js helper references. */
@@ -22,6 +21,8 @@ const nodeIsSet = nodeUtil && nodeUtil.isSet;
  * _.isSet(new WeakSet);
  * // => false
  */
-const isSet = nodeIsSet ? baseUnary(nodeIsSet) : baseIsSet;
+const isSet = nodeIsSet
+  ? value => nodeIsSet(value)
+  : baseIsSet;
 
 export default isSet;
diff --git a/isTypedArray.js b/isTypedArray.js
index 1dd4830a5..95e3166be 100644
--- a/isTypedArray.js
+++ b/isTypedArray.js
@@ -1,5 +1,4 @@
 import baseIsTypedArray from './_baseIsTypedArray.js';
-import baseUnary from './_baseUnary.js';
 import nodeUtil from './_nodeUtil.js';
 
 /* Node.js helper references. */
@@ -22,6 +21,8 @@ const nodeIsTypedArray = nodeUtil && nodeUtil.isTypedArray;
  * _.isTypedArray([]);
  * // => false
  */
-const isTypedArray = nodeIsTypedArray ? baseUnary(nodeIsTypedArray) : baseIsTypedArray;
+const isTypedArray = nodeIsTypedArray
+  ? value => nodeIsTypedArray(value)
+  : baseIsTypedArray;
 
 export default isTypedArray;
diff --git a/overArgs.js b/overArgs.js
index 7e7bc5243..187c9e11b 100644
--- a/overArgs.js
+++ b/overArgs.js
@@ -2,8 +2,6 @@ import apply from './_apply.js';
 import arrayMap from './_arrayMap.js';
 import baseFlatten from './_baseFlatten.js';
 import baseIteratee from './_baseIteratee.js';
-import baseUnary from './_baseUnary.js';
-import isArray from './isArray.js';
 
 /* Built-in method references for those with the same name as other `lodash` methods. */
 const nativeMin = Math.min;
@@ -40,10 +38,7 @@ const nativeMin = Math.min;
  * // => [100, 10]
  */
 function overArgs(func, ...transforms) {
-  transforms = (transforms.length == 1 && isArray(transforms[0]))
-    ? arrayMap(transforms[0], baseUnary(baseIteratee))
-    : arrayMap(baseFlatten(transforms, 1), baseUnary(baseIteratee));
-
+  transforms = arrayMap(transforms, transform => baseIteratee(transform));
   const funcsLength = transforms.length;
   return function(...args) {
     let index = -1;
diff --git a/unary.js b/unary.js
deleted file mode 100644
index cdb59ffb5..000000000
--- a/unary.js
+++ /dev/null
@@ -1,22 +0,0 @@
-import ary from './ary.js';
-
-/**
- * Creates a function that accepts up to one argument, ignoring any
- * additional arguments.
- *
- * @static
- * @memberOf _
- * @since 4.0.0
- * @category Function
- * @param {Function} func The function to cap arguments for.
- * @returns {Function} Returns the new capped function.
- * @example
- *
- * _.map(['6', '8', '10'], _.unary(parseInt));
- * // => [6, 8, 10]
- */
-function unary(func) {
-  return ary(func, 1);
-}
-
-export default unary;
diff --git a/without.js b/without.js
index 21ca42f8a..f1613b3bd 100644
--- a/without.js
+++ b/without.js
@@ -21,7 +21,8 @@ import isArrayLikeObject from './isArrayLikeObject.js';
  * _.without([2, 1, 2, 3], 1, 2);
  * // => [3]
  */
-const without = (array, ...values) =>
-  isArrayLikeObject(array) ? baseDifference(array, values) : [];
+function without(array, ...values) {
+  return isArrayLikeObject(array) ? baseDifference(array, values) : [];
+}
 
 export default without;