diff --git a/src/Composer/Autoload/ClassMapGenerator.php b/src/Composer/Autoload/ClassMapGenerator.php
index 649c700c8..5ff23921c 100644
--- a/src/Composer/Autoload/ClassMapGenerator.php
+++ b/src/Composer/Autoload/ClassMapGenerator.php
@@ -94,6 +94,10 @@ class ClassMapGenerator
             if ($blacklist && preg_match($blacklist, strtr(realpath($filePath), '\\', '/'))) {
                 continue;
             }
+            // check non-realpath of file for directories symlink in project dir
+            if ($blacklist && preg_match($blacklist, strtr($filePath, '\\', '/'))) {
+                continue;
+            }
 
             $classes = self::findClasses($filePath);
 
diff --git a/tests/Composer/Test/Autoload/AutoloadGeneratorTest.php b/tests/Composer/Test/Autoload/AutoloadGeneratorTest.php
index 22ceec030..5456769b8 100644
--- a/tests/Composer/Test/Autoload/AutoloadGeneratorTest.php
+++ b/tests/Composer/Test/Autoload/AutoloadGeneratorTest.php
@@ -23,6 +23,7 @@ use Composer\Repository\InstalledRepositoryInterface;
 use Composer\Installer\InstallationManager;
 use Composer\Config;
 use Composer\EventDispatcher\EventDispatcher;
+use Composer\Util\Platform;
 use PHPUnit_Framework_MockObject_MockObject as MockObject;
 
 class AutoloadGeneratorTest extends TestCase
@@ -1292,6 +1293,7 @@ EOF;
             ),
             'classmap' => array('composersrc/'),
             'exclude-from-classmap' => array(
+                '/composersrc/foo/bar/',
                 '/composersrc/excludedTests/',
                 '/composersrc/ClassToExclude.php',
                 '/composersrc/*/excluded/excsubpath',
@@ -1326,6 +1328,18 @@ EOF;
         file_put_contents($this->workingDir.'/composersrc/long/excluded/excsubpath/foo.php', '<?php class ClassExcludeMapFoo2 {}');
         file_put_contents($this->workingDir.'/composersrc/long/excluded/excsubpath/bar.php', '<?php class ClassExcludeMapBar {}');
 
+        // symlink directory in project directory in classmap
+        $this->fs->ensureDirectoryExists($this->workingDir.'/forks/bar/src/exclude');
+        $this->fs->ensureDirectoryExists($this->workingDir.'/composersrc/foo');
+
+        file_put_contents($this->workingDir.'/forks/bar/src/exclude/FooExclClass.php', '<?php class FooExclClass {};');
+        $target = $this->workingDir.'/forks/bar/';
+        $link = $this->workingDir.'/composersrc/foo/bar/';
+        $command = Platform::isWindows()
+            ? 'mklink /j "' . str_replace('/', '\\', $link) . '" "' . str_replace('/', '\\', $target)
+            : 'ln -s "' . $target . '" "' . $link;
+        exec($command);
+
         $this->generator->dump($this->config, $this->repository, $package, $this->im, 'composer', true, '_1');
 
         // Assert that autoload_classmap.php was correctly generated.