diff --git a/res/composer-schema.json b/res/composer-schema.json
index 905199247..6687de280 100644
--- a/res/composer-schema.json
+++ b/res/composer-schema.json
@@ -223,6 +223,10 @@
                 "files": {
                     "type": "array",
                     "description": "This is an array of files that are always required on every request."
+                },
+                "exclude-from-classmap": {
+                    "type": "array",
+                    "description": "This is an array of patterns to exclude from autoload classmap generation. (e.g. \"exclude-from-classmap\": [\"/test/\", \"/tests/\", \"/Tests/\"]"
                 }
             }
         },
diff --git a/src/Composer/Autoload/AutoloadGenerator.php b/src/Composer/Autoload/AutoloadGenerator.php
index 2359265bd..c65980697 100644
--- a/src/Composer/Autoload/AutoloadGenerator.php
+++ b/src/Composer/Autoload/AutoloadGenerator.php
@@ -27,6 +27,8 @@ use Composer\Script\ScriptEvents;
  */
 class AutoloadGenerator
 {
+    const EXCLUDE_PATTERN = '.*%s';
+
     /**
      * @var EventDispatcher
      */
@@ -154,6 +156,11 @@ EOF;
 EOF;
         }
 
+        $blacklist = '';
+        if(!empty($autoloads['exclude-from-classmap'])) {
+            $blacklist = '{(' . implode('|', $autoloads['exclude-from-classmap']) . ')}';
+        }
+
         // flatten array
         $classMap = array();
         if ($scanPsr0Packages) {
@@ -165,12 +172,7 @@ EOF;
                         if (!is_dir($dir)) {
                             continue;
                         }
-                        $whitelist = sprintf(
-                            '{%s/%s.+(?<!(?<!/)Test\.php)$}',
-                            preg_quote($dir),
-                            ($psrType === 'psr-4' || strpos($namespace, '_') === false) ? preg_quote(strtr($namespace, '\\', '/')) : ''
-                        );
-                        foreach (ClassMapGenerator::createMap($dir, $whitelist) as $class => $path) {
+                        foreach (ClassMapGenerator::createMap($dir, $blacklist) as $class => $path) {
                             if ('' === $namespace || 0 === strpos($class, $namespace)) {
                                 if (!isset($classMap[$class])) {
                                     $path = $this->getPathCode($filesystem, $basePath, $vendorPath, $path);
@@ -185,7 +187,7 @@ EOF;
 
         $autoloads['classmap'] = new \RecursiveIteratorIterator(new \RecursiveArrayIterator($autoloads['classmap']));
         foreach ($autoloads['classmap'] as $dir) {
-            foreach (ClassMapGenerator::createMap($dir) as $class => $path) {
+            foreach (ClassMapGenerator::createMap($dir, $blacklist) as $class => $path) {
                 $path = $this->getPathCode($filesystem, $basePath, $vendorPath, $path);
                 $classMap[$class] = $path.",\n";
             }
@@ -285,11 +287,19 @@ EOF;
         $psr4 = $this->parseAutoloadsType($packageMap, 'psr-4', $mainPackage);
         $classmap = $this->parseAutoloadsType($sortedPackageMap, 'classmap', $mainPackage);
         $files = $this->parseAutoloadsType($sortedPackageMap, 'files', $mainPackage);
+        $exclude = $this->parseAutoloadsType($sortedPackageMap, 'exclude-from-classmap', $mainPackage);
 
         krsort($psr0);
         krsort($psr4);
 
-        return array('psr-0' => $psr0, 'psr-4' => $psr4, 'classmap' => $classmap, 'files' => $files);
+        return
+            array(
+             'psr-0' => $psr0,
+             'psr-4' => $psr4,
+             'classmap' => $classmap,
+             'files' => $files,
+             'exclude-from-classmap' => $exclude
+            );
     }
 
     /**
@@ -597,6 +607,23 @@ FOOTER;
                         $path = $package->getTargetDir() . '/' . $path;
                     }
 
+                    if ($type === 'exclude-from-classmap') {
+                        // first escape user input
+                        $path = sprintf(self::EXCLUDE_PATTERN, preg_quote($path));
+
+                        if ($package === $mainPackage && $package->getTargetDir() && !is_readable($installPath.'/'.$path)) {
+                            // remove target-dir from classmap entries of the root package
+                            $targetDir = str_replace('\\<dirsep\\>', '[\\\\/]', preg_quote(str_replace(array('/', '\\'), '<dirsep>', $package->getTargetDir())));
+                            $path = ltrim(preg_replace('{^'.$targetDir.'}', '', ltrim($path, '\\/')), '\\/');
+                        }
+                        elseif($package !== $mainPackage && $package->getTargetDir() && !is_readable($installPath.'/'.$path)) {
+                            // add target-dir to exclude entries that don't have it
+                            $path = preg_quote($package->getTargetDir()) . '/' . $path;
+                        }
+                        $autoloads[] = empty($installPath) ? $path : preg_quote($installPath) . '/' . $path;
+                        continue;
+                    }
+
                     if (empty($installPath)) {
                         $autoloads[$namespace][] = empty($path) ? '.' : $path;
                     } else {
diff --git a/src/Composer/Autoload/ClassMapGenerator.php b/src/Composer/Autoload/ClassMapGenerator.php
index e9142c15f..5d45eb482 100644
--- a/src/Composer/Autoload/ClassMapGenerator.php
+++ b/src/Composer/Autoload/ClassMapGenerator.php
@@ -42,13 +42,13 @@ class ClassMapGenerator
      * Iterate over all files in the given directory searching for classes
      *
      * @param Iterator|string $path      The path to search in or an iterator
-     * @param string          $whitelist Regex that matches against the file path
+     * @param string          $blacklist Regex that matches against the file path that exclude from the classmap.
      *
      * @return array A class map array
      *
      * @throws \RuntimeException When the path is neither an existing file nor directory
      */
-    public static function createMap($path, $whitelist = null)
+    public static function createMap($path, $blacklist = '')
     {
         if (is_string($path)) {
             if (is_file($path)) {
@@ -72,7 +72,7 @@ class ClassMapGenerator
                 continue;
             }
 
-            if ($whitelist && !preg_match($whitelist, strtr($filePath, '\\', '/'))) {
+            if ($blacklist && preg_match($blacklist, strtr($filePath, '\\', '/'))) {
                 continue;
             }
 
diff --git a/tests/Composer/Test/Autoload/AutoloadGeneratorTest.php b/tests/Composer/Test/Autoload/AutoloadGeneratorTest.php
index 499f4de0d..4f91903cf 100644
--- a/tests/Composer/Test/Autoload/AutoloadGeneratorTest.php
+++ b/tests/Composer/Test/Autoload/AutoloadGeneratorTest.php
@@ -1016,6 +1016,36 @@ EOF;
         $this->assertEquals($expectedPsr4, file_get_contents($this->vendorDir.'/composer/autoload_psr4.php'));
     }
 
+    public function testExcludeFromClassmap()
+    {
+        $package = new Package('a', '1.0', '1.0');
+        $package->setAutoload(array(
+            'psr-0' => array(
+                'Main' => 'src/',
+            ),
+            'classmap' => array('composersrc/'),
+            'exclude-from-classmap' => array('/tests/'),
+        ));
+
+        $this->repository->expects($this->once())
+            ->method('getCanonicalPackages')
+            ->will($this->returnValue(array()));
+
+        $this->fs->ensureDirectoryExists($this->workingDir.'/composer');
+        $this->fs->ensureDirectoryExists($this->workingDir.'/src');
+
+        $this->fs->ensureDirectoryExists($this->workingDir.'/composersrc');
+        file_put_contents($this->workingDir.'/composersrc/foo.php', '<?php class ClassMapFoo {}');
+
+        $this->fs->ensureDirectoryExists($this->workingDir.'/composersrc/tests');
+        file_put_contents($this->workingDir.'/composersrc/tests/bar.php', '<?php class ClassExcludeMapFoo {}');
+
+        $this->generator->dump($this->config, $this->repository, $package, $this->im, 'composer', false, '_1');
+
+                // Assert that autoload_classmap.php was correctly generated.
+        $this->assertAutoloadFiles('classmap', $this->vendorDir.'/composer', 'classmap');
+    }
+
     private function assertAutoloadFiles($name, $dir, $type = 'namespaces')
     {
         $a = __DIR__.'/Fixtures/autoload_'.$name.'.php';