diff --git a/index.js b/index.js
index bcc8ee72a6..230fe70cb9 100644
--- a/index.js
+++ b/index.js
@@ -3,12 +3,26 @@ var setImmediate = require('set-immediate-shim');
 var relative = require('path').relative;
 var hasFlag = require('has-flag');
 var chalk = require('chalk');
+var join = require('path').join;
+var relative = require('path').relative;
 var serializeError = require('./lib/serialize-value');
 var Runner = require('./lib/runner');
 var send = require('./lib/send');
 var log = require('./lib/logger');
 
 var runner = new Runner();
+var xdgBasedir = require('xdg-basedir');
+var cache = require('cacha')(join(xdgBasedir.cache, 'ava'));
+var Configstore = require('configstore');
+var config = new Configstore('ava', {
+	lastCacheClean: Date.now()
+});
+var WEEK = 7 * 24 * 60 * 60 * 1000;
+
+if (Date.now() - config.get('lastCacheClean') > WEEK) {
+	config.set('lastCacheClean', Date.now());
+	cache.clean();
+}
 
 // note that test files have require('ava')
 require('./lib/babel').avaRequired = true;
diff --git a/lib/babel.js b/lib/babel.js
index a6b8890ea2..d4eeadd863 100644
--- a/lib/babel.js
+++ b/lib/babel.js
@@ -6,6 +6,11 @@ var resolveFrom = require('resolve-from');
 var hasGenerator = require('has-generator');
 var serializeValue = require('./serialize-value');
 var send = require('./send');
+var hasha = require('hasha');
+var hashObj = require('hash-obj');
+var xdgBasedir = require('xdg-basedir');
+var path = require('path');
+var cache = require('cacha')(path.join(xdgBasedir.cache, 'ava'));
 
 var testPath = process.argv[2];
 
@@ -31,24 +36,6 @@ var options = {
 	plugins: [powerAssert]
 };
 
-// check if test files required ava and show error, when they didn't
-exports.avaRequired = false;
-
-process.on('uncaughtException', function (exception) {
-	send('uncaughtException', {exception: serializeValue(exception)});
-});
-
-// include test file
-var transpiled = babel.transformFileSync(testPath, options);
-requireFromString(transpiled.code, testPath, {
-	appendPaths: module.paths
-});
-
-// if ava was not required, show an error
-if (!exports.avaRequired) {
-	throw new Error('No tests found in ' + testPath + ', make sure to import "ava" at the top of your test file');
-}
-
 // parse and re-emit ava messages
 process.on('message', function (message) {
 	if (!message.ava) {
@@ -82,6 +69,35 @@ process.on('ava-teardown', function () {
 	setTimeout(exit, 100);
 });
 
+process.on('uncaughtException', function (exception) {
+	send('uncaughtException', {exception: serializeValue(exception)});
+});
+
+var hash = hashObj({
+	code: hasha.fromFileSync(testPath),
+	avaVersion: require('../package.json').version
+});
+
+var code = cache.getSync(hash, 'utf8');
+
+if (code === undefined) {
+	code = babel.transformFileSync(testPath, options).code;
+	cache.setSync(hash, code, 'utf8');
+}
+
+// check if test files required ava and show error, when they didn't
+exports.avaRequired = false;
+
+// include test file
+requireFromString(code, testPath, {
+	appendPaths: module.paths
+});
+
+// if ava was not required, show an error
+if (!exports.avaRequired) {
+	throw new Error('No tests found in ' + testPath + ', make sure to import "ava" at the top of your test file');
+}
+
 function exit() {
 	send('teardown');
 }
diff --git a/package.json b/package.json
index e5851dbdaf..642d86b2d2 100644
--- a/package.json
+++ b/package.json
@@ -77,8 +77,10 @@
     "babel-plugin-espower": "^1.1.0",
     "babel-runtime": "^5.8.29",
     "bluebird": "^3.0.0",
+    "cacha": "^1.0.3",
     "chalk": "^1.0.0",
     "co-with-promise": "^4.6.0",
+    "configstore": "^1.3.0",
     "core-assert": "^0.1.0",
     "debug": "^2.2.0",
     "destroy-circular": "jamestalmage/destroy-circular#feeb7d1",
@@ -88,6 +90,8 @@
     "globby": "^4.0.0",
     "has-flag": "^1.0.0",
     "has-generator": "^1.0.0",
+    "hash-obj": "^1.0.0",
+    "hasha": "^2.0.2",
     "is-generator-fn": "^1.0.0",
     "is-promise": "^2.1.0",
     "loud-rejection": "^1.2.0",
@@ -102,7 +106,8 @@
     "resolve-from": "^1.0.0",
     "set-immediate-shim": "^1.0.1",
     "squeak": "^1.2.0",
-    "update-notifier": "^0.5.0"
+    "update-notifier": "^0.5.0",
+    "xdg-basedir": "^2.0.0"
   },
   "devDependencies": {
     "coveralls": "^2.11.4",