diff --git a/grunt/config/esvm.js b/grunt/config/esvm.js
index d81d39818..bcda6fef2 100644
--- a/grunt/config/esvm.js
+++ b/grunt/config/esvm.js
@@ -2,6 +2,8 @@ var utils = require('../utils');
 var _ = require('lodash');
 var join = require('path').join;
 
+var Version = require('../../scripts/Version');
+
 var defaultOpts = {
   directory: join(__dirname, '..', '..', '.esvm'),
   nodes: 1,
@@ -23,39 +25,28 @@ var defaultOpts = {
  * @param {[type]} target - the grunt target to configure
  */
 function setConfig(ref, target) {
-  var minorV = String(ref).replace(/^v/, '').replace(/(\d+\.\d+)\..+/, '$1');
+  var v = Version.fromBranch(String(ref).replace(/^v/, '').replace(/(\d+\.\d+)\..+/, '$1'));
+  var config = target.options.config = (target.options.config || {});
 
-  switch (minorV) {
-  case '0.90':
-  case '1.0':
-  case '1.1':
-    // no special treatment
-    break;
-  case '1.2':
-  case '1.3':
-  case '1.4':
-  case '1.5':
-  case '1.6':
-  case '1.x':
-    target.options.config = _.merge({
+  if (v.satisfies('^1.2')) {
+    _.merge(config, {
       'node.bench': true,
       'script.disable_dynamic': false
-    }, target.options.config);
-    break;
-  default:
-    target.options.config = _.merge({
+    });
+  }
+
+  if (v.satisfies('>=1.6')) {
+    _.merge(config, {
       'node.bench': true,
       'script.inline': true,
       'script.indexed': true
-    }, target.options.config);
-    break;
+    });
   }
 
+  _.defaultsDeep(target.options, defaultOpts);
 
-  target.options = _.merge({}, defaultOpts, target.options);
-
-  if (minorV === 'master') {
-    delete target.options.config['discovery.zen.ping_timeout'];
+  if (v.satisfies('>=1.6')) {
+    delete config['discovery.zen.ping_timeout'];
   }
 
   if (target.options.branch && !target.options.version) {
diff --git a/package.json b/package.json
index 3d6fefa69..e98c17a9f 100644
--- a/package.json
+++ b/package.json
@@ -72,7 +72,7 @@
     "nock": "~0.28.3",
     "open": "0.0.4",
     "optimist": "~0.6.0",
-    "semver": "~4.1.0",
+    "semver": "^4.3.6",
     "sinon": "~1.12.2",
     "split": "~0.3.2",
     "through2": "~0.6.3",
@@ -84,7 +84,7 @@
     "bluebird": "^2.9.14",
     "chalk": "^1.0.0",
     "forever-agent": "^0.6.0",
-    "lodash": "^3.9.3",
+    "lodash": "^3.10.0",
     "lodash-compat": "^3.0.0"
   },
   "repository": {
diff --git a/scripts/Version.js b/scripts/Version.js
new file mode 100644
index 000000000..1290b5609
--- /dev/null
+++ b/scripts/Version.js
@@ -0,0 +1,56 @@
+var _ = require('lodash');
+var package = require('../package.json');
+var branches = package.config.supported_es_branches;
+var semver = require('semver');
+
+var maxMinorVersion = function (majorV) {
+  var versions = branches.map(function (v) { return v + '.0'; });
+  return new Version(semver.maxSatisfying(versions, '^' + majorV));
+};
+
+function Version(v) {
+  this.version = v;
+  this.major = semver.major(v);
+  this.minor = semver.minor(v);
+  this.patch = semver.patch(v);
+}
+
+Version.fromBranch = function (branch) {
+  var m;
+
+  // master === the highest version number
+  if (branch === 'master') return new Version('2.0.0');
+
+  // n.m -> n.m.0
+  if (m = branch.match(/^\d+\.\d+$/)) return new Version(branch + '.0');
+
+  // n.x -> n.(maxVersion + 1).0
+  if (m = branch.match(/^(\d+)\.x$/i)) return maxMinorVersion(m[1]).increment('minor');
+
+  throw new Error('unable to convert branch "' + branch + '" to semver');
+};
+
+Version.prototype.increment = function (which) {
+  return new Version(semver.inc(this.version, which));
+};
+
+Version.prototype.satisfies = function (range) {
+  return semver.satisfies(this.version, range);
+};
+
+// merge a list of option objects, each of which has a "version" key dictating
+// the range of versions those options should be included in. Options are merged
+// in the order of the array
+Version.prototype.mergeOpts = function (opts, defaults) {
+  var self = this;
+
+  return opts
+  .filter(function (rule) {
+    return self.satisfies(rule.version);
+  })
+  .reduce(function (overrides, rule) {
+    return _.merge(overrides, _.omit(rule, 'version'));
+  }, defaults ? _.clone(defaults) : {});
+};
+
+module.exports = Version;
\ No newline at end of file
diff --git a/scripts/generate/js_api.js b/scripts/generate/js_api.js
index e70a4eba1..4cc607dc1 100644
--- a/scripts/generate/js_api.js
+++ b/scripts/generate/js_api.js
@@ -9,9 +9,9 @@ module.exports = function (branch, done) {
   var async = require('async');
   var chalk = require('chalk');
   var path = require('path');
-  var semver = require('semver');
   var fromRoot = path.join.bind(path, require('find-root')(__dirname));
   var templates = require('./templates');
+  var Version = require('../Version');
   var urlParamRE = /\{(\w+)\}/g;
 
   var files; // populated in readSpecFiles
@@ -19,34 +19,10 @@ module.exports = function (branch, done) {
   var docVars; // slightly modified clone of apiSpec for the docs
 
   var branchSuffix = utils.branchSuffix(branch);
-  var maxMinorVersion = (function () {
-    var branches = require(fromRoot('package.json')).config.supported_es_branches;
-    var top = branches.map(function (v) { return v + '.0'; }).sort(semver.compare).pop();
-    return top.split('.')[1];
-  }());
-
-  var branchAsVersion = (function () {
-    var m;
-
-    // master === the highest version number
-    if (branch === 'master') return '2.0.0';
-    // n.m -> n.m.0
-    if (m = branch.match(/^\d+\.\d+$/)) return branch + '.0';
-    // n.x -> n.(maxVersion + 1).0
-    if (m = branch.match(/^(\d+)\.x$/i)) return m[1] + '.' + (+maxMinorVersion + 1) + '.0';
-
-    throw new Error('unable to convert branch "' + branch + '" to semver');
-  }());
-
   var esDir = fromRoot('src/_elasticsearch_' + _.snakeCase(branch));
 
-  var overrides = require('./overrides')
-  .filter(function (rule) {
-    return semver.satisfies(branchAsVersion, rule.version);
-  })
-  .reduce(function (overrides, rule) {
-    return _.merge(overrides, _.omit(rule, 'version'));
-  }, {
+  var version = Version.fromBranch(branch);
+  var overrides = version.mergeOpts(require('./overrides'), {
     aliases: {},
     paramAsBody: {},
     clientActionModifier: false