diff --git a/.eslintrc.js b/.eslintrc.js
index abedf9c43..7420ca1a4 100644
--- a/.eslintrc.js
+++ b/.eslintrc.js
@@ -38,9 +38,7 @@ module.exports = {
       'requireReturnForObjectLiteral': false
     }],
 
-    'arrow-parens': ['error', 'as-needed', {
-      'requireForBlockBody': true
-    }],
+    'arrow-parens': ['error', 'always'],
 
     'arrow-spacing': ['error', {
       'before': true,
diff --git a/.internal/baseConforms.js b/.internal/baseConforms.js
index 53e2fd54f..1df2aed16 100644
--- a/.internal/baseConforms.js
+++ b/.internal/baseConforms.js
@@ -10,7 +10,7 @@ import keys from '../keys.js'
  */
 function baseConforms(source) {
   const props = keys(source)
-  return object => baseConformsTo(object, source, props)
+  return (object) => baseConformsTo(object, source, props)
 }
 
 export default baseConforms
diff --git a/.internal/baseDifference.js b/.internal/baseDifference.js
index f68a09895..07d1eefea 100644
--- a/.internal/baseDifference.js
+++ b/.internal/baseDifference.js
@@ -30,7 +30,7 @@ function baseDifference(array, values, iteratee, comparator) {
     return result
   }
   if (iteratee) {
-    values = arrayMap(values, value => iteratee(value))
+    values = arrayMap(values, (value) => iteratee(value))
   }
   if (comparator) {
     includes = arrayIncludesWith
diff --git a/.internal/baseIntersection.js b/.internal/baseIntersection.js
index fcbe9f259..c038ecc8b 100644
--- a/.internal/baseIntersection.js
+++ b/.internal/baseIntersection.js
@@ -31,7 +31,7 @@ function baseIntersection(arrays, iteratee, comparator) {
   while (othIndex--) {
     array = arrays[othIndex]
     if (othIndex && iteratee) {
-      array = arrayMap(array, value => iteratee(value))
+      array = arrayMap(array, (value) => iteratee(value))
     }
     maxLength = nativeMin(array.length, maxLength)
     caches[othIndex] = !comparator && (iteratee || (length >= 120 && array.length >= 120))
diff --git a/.internal/baseMatches.js b/.internal/baseMatches.js
index 012a04e5c..f6145fd2d 100644
--- a/.internal/baseMatches.js
+++ b/.internal/baseMatches.js
@@ -14,7 +14,7 @@ function baseMatches(source) {
   if (matchData.length == 1 && matchData[0][2]) {
     return matchesStrictComparable(matchData[0][0], matchData[0][1])
   }
-  return object => object === source || baseIsMatch(object, source, matchData)
+  return (object) => object === source || baseIsMatch(object, source, matchData)
 }
 
 export default baseMatches
diff --git a/.internal/baseOrderBy.js b/.internal/baseOrderBy.js
index fe6c459b6..1e2fd0c8d 100644
--- a/.internal/baseOrderBy.js
+++ b/.internal/baseOrderBy.js
@@ -14,10 +14,10 @@ import compareMultiple from './compareMultiple.js'
  */
 function baseOrderBy(collection, iteratees, orders) {
   let index = -1
-  iteratees = iteratees.length ? iteratees : [value => value]
+  iteratees = iteratees.length ? iteratees : [(value) => value]
 
   const result = baseMap(collection, (value, key, collection) => {
-    const criteria = arrayMap(iteratees, iteratee => iteratee(value))
+    const criteria = arrayMap(iteratees, (iteratee) => iteratee(value))
     return { 'criteria': criteria, 'index': ++index, 'value': value }
   })
 
diff --git a/.internal/baseProperty.js b/.internal/baseProperty.js
index a26fe0d8b..48b94ce74 100644
--- a/.internal/baseProperty.js
+++ b/.internal/baseProperty.js
@@ -6,7 +6,7 @@
  * @returns {Function} Returns the new accessor function.
  */
 function baseProperty(key) {
-  return object => object == null ? undefined : object[key]
+  return (object) => object == null ? undefined : object[key]
 }
 
 export default baseProperty
diff --git a/.internal/basePropertyDeep.js b/.internal/basePropertyDeep.js
index 2dbe3f2ef..32a12b9d3 100644
--- a/.internal/basePropertyDeep.js
+++ b/.internal/basePropertyDeep.js
@@ -8,7 +8,7 @@ import baseGet from './baseGet.js'
  * @returns {Function} Returns the new accessor function.
  */
 function basePropertyDeep(path) {
-  return object => baseGet(object, path)
+  return (object) => baseGet(object, path)
 }
 
 export default basePropertyDeep
diff --git a/.internal/basePropertyOf.js b/.internal/basePropertyOf.js
index d9ecf59a3..a9485296d 100644
--- a/.internal/basePropertyOf.js
+++ b/.internal/basePropertyOf.js
@@ -6,7 +6,7 @@
  * @returns {Function} Returns the new accessor function.
  */
 function basePropertyOf(object) {
-  return key => object == null ? undefined : object[key]
+  return (key) => object == null ? undefined : object[key]
 }
 
 export default basePropertyOf
diff --git a/.internal/basePullAll.js b/.internal/basePullAll.js
index 83dba6f44..7ddfa5440 100644
--- a/.internal/basePullAll.js
+++ b/.internal/basePullAll.js
@@ -27,7 +27,7 @@ function basePullAll(array, values, iteratee, comparator) {
     values = copyArray(values)
   }
   if (iteratee) {
-    seen = arrayMap(array, value => iteratee(value))
+    seen = arrayMap(array, (value) => iteratee(value))
   }
   while (++index < length) {
     let fromIndex = 0
diff --git a/.internal/baseSortedIndex.js b/.internal/baseSortedIndex.js
index 6deb1b391..87e5db485 100644
--- a/.internal/baseSortedIndex.js
+++ b/.internal/baseSortedIndex.js
@@ -34,7 +34,7 @@ function baseSortedIndex(array, value, retHighest) {
     }
     return high
   }
-  return baseSortedIndexBy(array, value, value => value, retHighest)
+  return baseSortedIndexBy(array, value, (value) => value, retHighest)
 }
 
 export default baseSortedIndex
diff --git a/.internal/baseValues.js b/.internal/baseValues.js
index 1ec119bc8..6a43d9baa 100644
--- a/.internal/baseValues.js
+++ b/.internal/baseValues.js
@@ -11,7 +11,7 @@ import arrayMap from './arrayMap.js'
  * @returns {Object} Returns the array of property values.
  */
 function baseValues(object, props) {
-  return arrayMap(props, key => object[key])
+  return arrayMap(props, (key) => object[key])
 }
 
 export default baseValues
diff --git a/.internal/createCompounder.js b/.internal/createCompounder.js
index 4b9b88936..15b0157ab 100644
--- a/.internal/createCompounder.js
+++ b/.internal/createCompounder.js
@@ -13,7 +13,7 @@ const reApos = /['\u2019]/g
  * @returns {Function} Returns the new compounder function.
  */
 function createCompounder(callback) {
-  return string => (
+  return (string) => (
     arrayReduce(words(toString(string).replace(reApos, '')), callback, '')
   )
 }
diff --git a/.internal/createSet.js b/.internal/createSet.js
index bb624bd2b..0e86dc5c7 100644
--- a/.internal/createSet.js
+++ b/.internal/createSet.js
@@ -11,7 +11,7 @@ const INFINITY = 1 / 0
  * @returns {Object} Returns the new set.
  */
 const createSet = (Set && (1 / setToArray(new Set([,-0]))[1]) == INFINITY)
-  ? values => new Set(values)
+  ? (values) => new Set(values)
   : () => {}
 
 export default createSet
diff --git a/.internal/getSymbols.js b/.internal/getSymbols.js
index 4b51a3da8..cc1b78598 100644
--- a/.internal/getSymbols.js
+++ b/.internal/getSymbols.js
@@ -18,7 +18,7 @@ const getSymbols = !nativeGetSymbols ? () => [] : (object) => {
     return []
   }
   object = Object(object)
-  return arrayFilter(nativeGetSymbols(object), symbol => propertyIsEnumerable.call(object, symbol))
+  return arrayFilter(nativeGetSymbols(object), (symbol) => propertyIsEnumerable.call(object, symbol))
 }
 
 export default getSymbols
diff --git a/.internal/setToPairs.js b/.internal/setToPairs.js
index 3f2d1d9d7..1d8ed7de7 100644
--- a/.internal/setToPairs.js
+++ b/.internal/setToPairs.js
@@ -9,7 +9,7 @@ function setToPairs(set) {
   let index = -1
   const result = Array(set.size)
 
-  set.forEach(value =>
+  set.forEach((value) =>
     result[++index] = [value, value]
   )
   return result
diff --git a/escape.js b/escape.js
index 4a5445e94..e3fdc5e2e 100644
--- a/escape.js
+++ b/escape.js
@@ -43,7 +43,7 @@ const reHasUnescapedHtml = RegExp(reUnescapedHtml.source)
 function escape(string) {
   string = toString(string)
   return (string && reHasUnescapedHtml.test(string))
-    ? string.replace(reUnescapedHtml, chr => htmlEscapes[chr])
+    ? string.replace(reUnescapedHtml, (chr) => htmlEscapes[chr])
     : string
 }
 
diff --git a/forOwn.js b/forOwn.js
index f38213ac5..a7d3f55e6 100644
--- a/forOwn.js
+++ b/forOwn.js
@@ -25,7 +25,7 @@
  */
 function forOwn(object, iteratee) {
   if (object != null) {
-    Object.keys(Object(object)).forEach(key => iteratee(object[key], key, object))
+    Object.keys(Object(object)).forEach((key) => iteratee(object[key], key, object))
   }
 }
 
diff --git a/functions.js b/functions.js
index 251c4181f..3242c835a 100644
--- a/functions.js
+++ b/functions.js
@@ -23,7 +23,7 @@ function functions(object) {
   if (object == null) {
     return []
   }
-  return Object.keys(object).filter(key => typeof object[key] == 'function')
+  return Object.keys(object).filter((key) => typeof object[key] == 'function')
 }
 
 export default functions
diff --git a/isArrayBuffer.js b/isArrayBuffer.js
index 83f5c0786..ab50e52d1 100644
--- a/isArrayBuffer.js
+++ b/isArrayBuffer.js
@@ -21,7 +21,7 @@ const nodeIsArrayBuffer = nodeUtil && nodeUtil.isArrayBuffer
  * // => false
  */
 const isArrayBuffer = nodeIsArrayBuffer
-  ? value => nodeIsArrayBuffer(value)
-  : value => isObjectLike(value) && baseGetTag(value) == '[object ArrayBuffer]'
+  ? (value) => nodeIsArrayBuffer(value)
+  : (value) => isObjectLike(value) && baseGetTag(value) == '[object ArrayBuffer]'
 
 export default isArrayBuffer
diff --git a/isDate.js b/isDate.js
index 2a202ba02..c1787c3e6 100644
--- a/isDate.js
+++ b/isDate.js
@@ -21,7 +21,7 @@ const nodeIsDate = nodeUtil && nodeUtil.isDate
  * // => false
  */
 const isDate = nodeIsDate
-  ? value => nodeIsDate(value)
-  : value => isObjectLike(value) && baseGetTag(value) == '[object Date]'
+  ? (value) => nodeIsDate(value)
+  : (value) => isObjectLike(value) && baseGetTag(value) == '[object Date]'
 
 export default isDate
diff --git a/isMap.js b/isMap.js
index b1f9650e1..af7533d4a 100644
--- a/isMap.js
+++ b/isMap.js
@@ -21,7 +21,7 @@ const nodeIsMap = nodeUtil && nodeUtil.isMap
  * // => false
  */
 const isMap = nodeIsMap
-  ? value => nodeIsMap(value)
-  : value => isObjectLike(value) && getTag(value) == '[object Map]'
+  ? (value) => nodeIsMap(value)
+  : (value) => isObjectLike(value) && getTag(value) == '[object Map]'
 
 export default isMap
diff --git a/isRegExp.js b/isRegExp.js
index c409582c2..54d100bf1 100644
--- a/isRegExp.js
+++ b/isRegExp.js
@@ -21,7 +21,7 @@ const nodeIsRegExp = nodeUtil && nodeUtil.isRegExp
  * // => false
  */
 const isRegExp = nodeIsRegExp
-  ? value => nodeIsRegExp(value)
-  : value => isObjectLike(value) && baseGetTag(value) == '[object RegExp]'
+  ? (value) => nodeIsRegExp(value)
+  : (value) => isObjectLike(value) && baseGetTag(value) == '[object RegExp]'
 
 export default isRegExp
diff --git a/isSet.js b/isSet.js
index 6a3d21485..6b8606c62 100644
--- a/isSet.js
+++ b/isSet.js
@@ -20,7 +20,7 @@ const nodeIsSet = nodeUtil && nodeUtil.isSet
  * // => false
  */
 const isSet = nodeIsSet
-  ? value => nodeIsSet(value)
-  : value => typeof value == 'object' && value != null && getTag(value) == '[object Set]'
+  ? (value) => nodeIsSet(value)
+  : (value) => typeof value == 'object' && value != null && getTag(value) == '[object Set]'
 
 export default isSet
diff --git a/isTypedArray.js b/isTypedArray.js
index 89259a189..d39ccfcce 100644
--- a/isTypedArray.js
+++ b/isTypedArray.js
@@ -23,7 +23,7 @@ const nodeIsTypedArray = nodeUtil && nodeUtil.isTypedArray
  * // => false
  */
 const isTypedArray = nodeIsTypedArray
-  ? value => nodeIsTypedArray(value)
-  : value => typeof value == 'object' && value != null && reTypedTag.test(getTag(value))
+  ? (value) => nodeIsTypedArray(value)
+  : (value) => typeof value == 'object' && value != null && reTypedTag.test(getTag(value))
 
 export default isTypedArray
diff --git a/mean.js b/mean.js
index 214ac18bd..8f6d317f7 100644
--- a/mean.js
+++ b/mean.js
@@ -13,7 +13,7 @@ import baseMean from './meanBy.js'
  * // => 5
  */
 function mean(array) {
-  return baseMean(array, value => value)
+  return baseMean(array, (value) => value)
 }
 
 export default mean
diff --git a/method.js b/method.js
index 74f1e36a1..650f1dee5 100644
--- a/method.js
+++ b/method.js
@@ -23,7 +23,7 @@ import invoke from './invoke.js'
  * // => [2, 1]
  */
 function method(path, args) {
-  return object => invoke(object, path, args)
+  return (object) => invoke(object, path, args)
 }
 
 export default method
diff --git a/methodOf.js b/methodOf.js
index cc66a6196..dbf51cf3d 100644
--- a/methodOf.js
+++ b/methodOf.js
@@ -22,7 +22,7 @@ import invoke from './invoke.js'
  * // => [2, 0]
  */
 function methodOf(object, args) {
-  return path => invoke(object, path, args)
+  return (path) => invoke(object, path, args)
 }
 
 export default methodOf
diff --git a/over.js b/over.js
index df3684e62..644692d90 100644
--- a/over.js
+++ b/over.js
@@ -18,7 +18,7 @@ import arrayMap from './.internal/arrayMap.js'
  */
 function over(iteratees) {
   return function(...args) {
-    return arrayMap(iteratees, iteratee => iteratee.apply(this, args))
+    return arrayMap(iteratees, (iteratee) => iteratee.apply(this, args))
   }
 }
 
diff --git a/overEvery.js b/overEvery.js
index 1b8a20ad4..28e81d00c 100644
--- a/overEvery.js
+++ b/overEvery.js
@@ -24,7 +24,7 @@ import arrayEvery from './.internal/arrayEvery.js'
  */
 function overEvery(iteratees) {
   return function(...args) {
-    return arrayEvery(iteratees, iteratee => iteratee.apply(this, args))
+    return arrayEvery(iteratees, (iteratee) => iteratee.apply(this, args))
   }
 }
 
diff --git a/overSome.js b/overSome.js
index bf36b7754..d07e9a052 100644
--- a/overSome.js
+++ b/overSome.js
@@ -24,7 +24,7 @@ import arraySome from './.internal/arraySome.js'
  */
 function overSome(iteratees) {
   return function(...args) {
-    return arraySome(iteratees, iteratee => iteratee.apply(this, args))
+    return arraySome(iteratees, (iteratee) => iteratee.apply(this, args))
   }
 }
 
diff --git a/pickBy.js b/pickBy.js
index b3f807cc6..c6d4409bb 100644
--- a/pickBy.js
+++ b/pickBy.js
@@ -22,7 +22,7 @@ function pickBy(object, predicate) {
   if (object == null) {
     return {}
   }
-  const props = arrayMap(getAllKeysIn(object), prop => [prop])
+  const props = arrayMap(getAllKeysIn(object), (prop) => [prop])
   return basePickBy(object, props, (value, path) => predicate(value, path[0]))
 }
 
diff --git a/propertyOf.js b/propertyOf.js
index fd8d9b8ea..ed6daac0b 100644
--- a/propertyOf.js
+++ b/propertyOf.js
@@ -20,7 +20,7 @@ import baseGet from './.internal/baseGet.js'
  * // => [2, 0]
  */
 function propertyOf(object) {
-  return path => object == null ? undefined : baseGet(object, path)
+  return (path) => object == null ? undefined : baseGet(object, path)
 }
 
 export default propertyOf
diff --git a/pullAt.js b/pullAt.js
index 0d25dcb32..4900c5292 100644
--- a/pullAt.js
+++ b/pullAt.js
@@ -31,7 +31,7 @@ function pullAt(array, ...indexes) {
   const length = array == null ? 0 : array.length
   const result = baseAt(array, indexes)
 
-  basePullAt(array, arrayMap(indexes, index => isIndex(index, length) ? +index : index).sort(compareAscending))
+  basePullAt(array, arrayMap(indexes, (index) => isIndex(index, length) ? +index : index).sort(compareAscending))
   return result
 }
 
diff --git a/sum.js b/sum.js
index d28629776..c9c0c277c 100644
--- a/sum.js
+++ b/sum.js
@@ -14,7 +14,7 @@ import baseSum from './.internal/baseSum.js'
  */
 function sum(array) {
   return (array != null && array.length)
-    ? baseSum(array, value => value)
+    ? baseSum(array, (value) => value)
     : 0
 }
 
diff --git a/template.js b/template.js
index 39e4c9a98..7ce21a245 100644
--- a/template.js
+++ b/template.js
@@ -182,7 +182,7 @@ function template(string, options) {
     // Escape characters that can't be included in string literals.
     source += string
       .slice(index, offset)
-      .replace(reUnescapedString, chr => `\\${ stringEscapes[chr] }`)
+      .replace(reUnescapedString, (chr) => `\\${ stringEscapes[chr] }`)
 
     // Replace delimiters with snippets.
     if (escapeValue) {
diff --git a/toString.js b/toString.js
index dea8183a3..307e8da48 100644
--- a/toString.js
+++ b/toString.js
@@ -37,7 +37,7 @@ function toString(value) {
   }
   if (Array.isArray(value)) {
     // Recursively convert values (susceptible to call stack limits).
-    return `${ arrayMap(value, other => other == null ? other : toString(other)) }`
+    return `${ arrayMap(value, (other) => other == null ? other : toString(other)) }`
   }
   if (isSymbol(value)) {
     return symbolToString ? symbolToString.call(value) : ''
diff --git a/unescape.js b/unescape.js
index e10d3cdc2..cb3c09ece 100644
--- a/unescape.js
+++ b/unescape.js
@@ -34,7 +34,7 @@ const reHasEscapedHtml = RegExp(reEscapedHtml.source)
 function unescape(string) {
   string = toString(string)
   return (string && reHasEscapedHtml.test(string))
-    ? string.replace(reEscapedHtml, entity => htmlUnescapes[entity])
+    ? string.replace(reEscapedHtml, (entity) => htmlUnescapes[entity])
     : string
 }
 
diff --git a/unzip.js b/unzip.js
index 5dc5e385d..a5223e809 100644
--- a/unzip.js
+++ b/unzip.js
@@ -36,7 +36,7 @@ function unzip(array) {
       return true
     }
   })
-  return baseTimes(length, index => arrayMap(array, baseProperty(index)))
+  return baseTimes(length, (index) => arrayMap(array, baseProperty(index)))
 }
 
 export default unzip
diff --git a/unzipWith.js b/unzipWith.js
index b6586523f..36137aa89 100644
--- a/unzipWith.js
+++ b/unzipWith.js
@@ -25,7 +25,7 @@ function unzipWith(array, iteratee) {
     return []
   }
   const result = unzip(array)
-  return arrayMap(result, group => iteratee.apply(undefined, group))
+  return arrayMap(result, (group) => iteratee.apply(undefined, group))
 }
 
 export default unzipWith