diff --git a/index.js b/index.js
index 59384f654..d9bd7f9e0 100644
--- a/index.js
+++ b/index.js
@@ -3,13 +3,14 @@ require('./lib/babel').avaRequired();
 var setImmediate = require('set-immediate-shim');
 var hasFlag = require('has-flag');
 var chalk = require('chalk');
+var join = require('path').join;
 var relative = require('path').relative;
 var serializeError = require('destroy-circular');
 var Runner = require('./lib/runner');
 var log = require('./lib/logger');
 var runner = new Runner();
 var xdgBasedir = require('xdg-basedir');
-var cache = require('cacha')(xdgBasedir.cache + '/ava');
+var cache = require('cacha')(join(xdgBasedir.cache, 'ava'));
 var Configstore = require('configstore');
 var config = new Configstore('ava', {
 	lastCacheClean: Date.now()
diff --git a/lib/babel.js b/lib/babel.js
index fccf1bdf9..4d9e8afc5 100644
--- a/lib/babel.js
+++ b/lib/babel.js
@@ -5,7 +5,8 @@ var requireFromString = require('require-from-string');
 var hasha = require('hasha');
 var hashObj = require('hash-obj');
 var xdgBasedir = require('xdg-basedir');
-var cache = require('cacha')(xdgBasedir.cache + '/ava');
+var path = require('path');
+var cache = require('cacha')(path.join(xdgBasedir.cache, 'ava'));
 
 var hasGenerators = parseInt(process.version.slice(1), 10) > 0;
 var testPath = process.argv[2];