diff --git a/fp/_baseConvert.js b/fp/_baseConvert.js
index 9eaa8212f..d0504cacc 100644
--- a/fp/_baseConvert.js
+++ b/fp/_baseConvert.js
@@ -65,6 +65,8 @@ function baseConvert(util, name, func, options) {
       rearg = helpers.rearg,
       spread = helpers.spread;
 
+  var aryMethodKeys = keys(mapping.aryMethod);
+
   var baseArity = function(func, n) {
     return n == 2
       ? function(a, b) { return func.apply(undefined, arguments); }
@@ -210,8 +212,8 @@ function baseConvert(util, name, func, options) {
       }
     }
     var result;
-    each(mapping.caps, function(cap) {
-      each(mapping.aryMethod[cap], function(otherName) {
+    each(aryMethodKeys, function(aryKey) {
+      each(mapping.aryMethod[aryKey], function(otherName) {
         if (name == otherName) {
           var aryN = !isLib && mapping.iterateeAry[name],
               spreadStart = mapping.methodSpread[name];
@@ -219,17 +221,17 @@ function baseConvert(util, name, func, options) {
           result = wrapped;
           if (config.fixed) {
             result = spreadStart === undefined
-              ? ary(result, cap)
+              ? ary(result, aryKey)
               : spread(result, spreadStart);
           }
-          if (config.rearg && cap > 1 && (forceRearg || !mapping.skipRearg[name])) {
-            result = rearg(result, mapping.methodRearg[name] || mapping.aryRearg[cap]);
+          if (config.rearg && aryKey > 1 && (forceRearg || !mapping.skipRearg[name])) {
+            result = rearg(result, mapping.methodRearg[name] || mapping.aryRearg[aryKey]);
           }
           if (config.cap && aryN) {
             result = iterateeAry(result, aryN);
           }
-          if (config.curry && cap > 1) {
-            result = curry(result, cap);
+          if (config.curry && aryKey > 1) {
+            result = curry(result, aryKey);
           }
           return false;
         }
@@ -252,8 +254,8 @@ function baseConvert(util, name, func, options) {
 
   // Iterate over methods for the current ary cap.
   var pairs = [];
-  each(mapping.caps, function(cap) {
-    each(mapping.aryMethod[cap], function(key) {
+  each(aryMethodKeys, function(aryKey) {
+    each(mapping.aryMethod[aryKey], function(key) {
       var func = _[mapping.remap[key] || key];
       if (func) {
         pairs.push([key, wrap(key, func)]);
diff --git a/fp/_mapping.js b/fp/_mapping.js
index 4726799a1..56ac6ef8e 100644
--- a/fp/_mapping.js
+++ b/fp/_mapping.js
@@ -38,55 +38,52 @@ exports.aliasToReal = {
 
 /** Used to map ary to method names. */
 exports.aryMethod = {
-  1: [
-      'attempt', 'castArray', 'ceil', 'create', 'curry', 'curryRight', 'floor',
-      'fromPairs', 'invert', 'iteratee', 'memoize', 'method', 'methodOf', 'mixin',
-      'over', 'overEvery', 'overSome', 'rest', 'reverse', 'round', 'runInContext',
-      'spread', 'template', 'trim', 'trimEnd', 'trimStart', 'uniqueId', 'words'
-    ],
-  2: [
-      'add', 'after', 'ary', 'assign', 'assignIn', 'at', 'before', 'bind', 'bindKey',
-      'chunk', 'cloneDeepWith', 'cloneWith', 'concat', 'countBy', 'curryN',
-      'curryRightN', 'debounce', 'defaults', 'defaultsDeep', 'delay', 'difference',
-      'drop', 'dropRight', 'dropRightWhile', 'dropWhile', 'endsWith', 'eq', 'every',
-      'filter', 'find', 'find', 'findIndex', 'findKey', 'findLast', 'findLastIndex',
-      'findLastKey', 'flatMap', 'flattenDepth', 'forEach', 'forEachRight', 'forIn',
-      'forInRight', 'forOwn', 'forOwnRight', 'get', 'groupBy', 'gt', 'gte', 'has',
-      'hasIn', 'includes', 'indexOf', 'intersection', 'invertBy', 'invoke', 'invokeMap',
-      'isEqual', 'isMatch', 'join', 'keyBy', 'lastIndexOf', 'lt', 'lte', 'map',
-      'mapKeys', 'mapValues', 'matchesProperty', 'maxBy', 'merge', 'minBy', 'omit',
-      'omitBy', 'orderBy', 'overArgs', 'pad', 'padEnd', 'padStart', 'parseInt',
-      'partial', 'partialRight', 'partition', 'pick', 'pickBy', 'pull', 'pullAll',
-      'pullAt', 'random', 'range', 'rangeRight', 'rearg', 'reject', 'remove',
-      'repeat', 'result', 'sampleSize', 'some', 'sortBy', 'sortedIndex',
-      'sortedIndexOf', 'sortedLastIndex', 'sortedLastIndexOf', 'sortedUniqBy',
-      'split', 'startsWith', 'subtract', 'sumBy', 'take', 'takeRight', 'takeRightWhile',
-      'takeWhile', 'tap', 'throttle', 'thru', 'times', 'trimChars', 'trimCharsEnd',
-      'trimCharsStart', 'truncate', 'union', 'uniqBy', 'uniqWith', 'unset',
-      'unzipWith', 'without', 'wrap', 'xor', 'zip', 'zipObject', 'zipObjectDeep'
-    ],
-  3: [
-      'assignInWith', 'assignWith', 'clamp', 'differenceBy', 'differenceWith',
-      'getOr', 'inRange', 'intersectionBy', 'intersectionWith', 'isEqualWith',
-      'isMatchWith', 'mergeWith', 'pullAllBy', 'reduce', 'reduceRight', 'replace',
-      'set', 'slice', 'sortedIndexBy', 'sortedLastIndexBy', 'transform', 'unionBy',
-      'unionWith', 'xorBy', 'xorWith', 'zipWith'
-    ],
-  4: [
-      'fill', 'setWith'
-    ]
+  '1': [
+    'attempt', 'castArray', 'ceil', 'create', 'curry', 'curryRight', 'floor',
+    'fromPairs', 'invert', 'iteratee', 'memoize', 'method', 'methodOf', 'mixin',
+    'over', 'overEvery', 'overSome', 'rest', 'reverse', 'round', 'runInContext',
+    'spread', 'template', 'trim', 'trimEnd', 'trimStart', 'uniqueId', 'words'
+  ],
+  '2': [
+    'add', 'after', 'ary', 'assign', 'assignIn', 'at', 'before', 'bind', 'bindKey',
+    'chunk', 'cloneDeepWith', 'cloneWith', 'concat', 'countBy', 'curryN',
+    'curryRightN', 'debounce', 'defaults', 'defaultsDeep', 'delay', 'difference',
+    'drop', 'dropRight', 'dropRightWhile', 'dropWhile', 'endsWith', 'eq', 'every',
+    'filter', 'find', 'find', 'findIndex', 'findKey', 'findLast', 'findLastIndex',
+    'findLastKey', 'flatMap', 'flattenDepth', 'forEach', 'forEachRight', 'forIn',
+    'forInRight', 'forOwn', 'forOwnRight', 'get', 'groupBy', 'gt', 'gte', 'has',
+    'hasIn', 'includes', 'indexOf', 'intersection', 'invertBy', 'invoke', 'invokeMap',
+    'isEqual', 'isMatch', 'join', 'keyBy', 'lastIndexOf', 'lt', 'lte', 'map',
+    'mapKeys', 'mapValues', 'matchesProperty', 'maxBy', 'merge', 'minBy', 'omit',
+    'omitBy', 'orderBy', 'overArgs', 'pad', 'padEnd', 'padStart', 'parseInt',
+    'partial', 'partialRight', 'partition', 'pick', 'pickBy', 'pull', 'pullAll',
+    'pullAt', 'random', 'range', 'rangeRight', 'rearg', 'reject', 'remove',
+    'repeat', 'result', 'sampleSize', 'some', 'sortBy', 'sortedIndex',
+    'sortedIndexOf', 'sortedLastIndex', 'sortedLastIndexOf', 'sortedUniqBy',
+    'split', 'startsWith', 'subtract', 'sumBy', 'take', 'takeRight', 'takeRightWhile',
+    'takeWhile', 'tap', 'throttle', 'thru', 'times', 'trimChars', 'trimCharsEnd',
+    'trimCharsStart', 'truncate', 'union', 'uniqBy', 'uniqWith', 'unset',
+    'unzipWith', 'without', 'wrap', 'xor', 'zip', 'zipObject', 'zipObjectDeep'
+  ],
+  '3': [
+    'assignInWith', 'assignWith', 'clamp', 'differenceBy', 'differenceWith',
+    'getOr', 'inRange', 'intersectionBy', 'intersectionWith', 'isEqualWith',
+    'isMatchWith', 'mergeWith', 'pullAllBy', 'reduce', 'reduceRight', 'replace',
+    'set', 'slice', 'sortedIndexBy', 'sortedLastIndexBy', 'transform', 'unionBy',
+    'unionWith', 'xorBy', 'xorWith', 'zipWith'
+  ],
+  '4': [
+    'fill', 'setWith'
+  ]
 };
 
 /** Used to map ary to rearg configs. */
 exports.aryRearg = {
-  2: [1, 0],
-  3: [2, 0, 1],
-  4: [3, 2, 0, 1]
+  '2': [1, 0],
+  '3': [2, 0, 1],
+  '4': [3, 2, 0, 1]
 };
 
-/** Used to iterate `mapping.aryMethod` keys. */
-exports.caps = [1, 2, 3, 4];
-
 /** Used to map method names to their iteratee ary. */
 exports.iterateeAry = {
   'assignWith': 2,