Travis is not ready for PSR4 yet.

autoload.php

@@ -0,0 +1,28 @@
+<?php
+/**
+ * PSR-4 compliant autoloader.
+ *
+ * This will be removed when Composer supports PSR-4 natively.
+ *
+ * @param string $fqcn The fully-qualified class name.
+ *
+ * @return void
+ * @link https://github.com/php-fig/fig-standards/blob/master/accepted/PSR-4-autoloader.md
+ * @link https://github.com/php-fig/fig-standards/blob/master/accepted/PSR-4-autoloader-examples.md
+ */
+spl_autoload_register(function ($fqcn) {
+    $prefix = 'Jeremeamia\\SuperClosure\\';
+    $baseDir = __DIR__ . '/src/';
+
+    $prefixLength = strlen($prefix);
+    if (strncmp($prefix, $fqcn, $prefixLength) !== 0) {
+        // Class doesn't match prefix
+        return;
+    }
+
+    $className = substr($fqcn, $prefixLength);
+    $filePath = $baseDir . str_replace('\\', '/', $className) . '.php';
+    if (is_readable($filePath)) {
+        require $filePath;
+    }
+});

composer.json

@@ -21,11 +21,8 @@
         "phpunit/phpunit": "~3.7"
     },
     "autoload": {
-        "psr-4": {
-            "Jeremeamia\\SuperClosure\\": "src/",
-            "Jeremeamia\\SuperClosure\\Test\\": "tests/"
-        },
         "files": [
+            "autoload.php",
             "src/functions.php"
         ]
     }

tests/bootstrap.php

@@ -1,4 +1,22 @@
 <?php
 
-date_default_timezone_set('America/Los_Angeles');
+date_default_timezone_set('UTC');
 require __DIR__ . '/../vendor/autoload.php';
+
+// Register another PSR-4-compliant autoloader for loading test classes
+spl_autoload_register(function ($fqcn) {
+    $prefix = 'Jeremeamia\\SuperClosure\\Test\\';
+    $baseDir = __DIR__ . '/';
+
+    $prefixLength = strlen($prefix);
+    if (strncmp($prefix, $fqcn, $prefixLength) !== 0) {
+        // Class doesn't match prefix
+        return;
+    }
+
+    $className = substr($fqcn, $prefixLength);
+    $filePath = $baseDir . str_replace('\\', '/', $className) . '.php';
+    if (is_readable($filePath)) {
+        require $filePath;
+    }
+});