diff --git a/Extractor/ApiDocExtractor.php b/Extractor/ApiDocExtractor.php
index 19f3104..725ddfc 100644
--- a/Extractor/ApiDocExtractor.php
+++ b/Extractor/ApiDocExtractor.php
@@ -374,12 +374,21 @@ class ApiDocExtractor
         }
 
         $collectionData = array();
-        preg_match_all("/array<(.*)>(\\s+as\\s+(.*))?/", $input['class'], $collectionData);
 
-        if (count($collectionData[0]) > 0) {
+        /*
+         * Match array<Fully\Qualified\ClassName> as alias; "as alias" optional.
+         */
+        if (preg_match_all("/^array<([A-Za-z]+[A-Za-z0-9_]*(?:\\\\[A-Za-z]+[A-Za-z0-9_]*)*)>(?:\\s+as\\s+(.+))?$/", $input['class'], $collectionData)) {
             $input['class'] = $collectionData[1][0];
             $input['collection'] = true;
-            $input['collectionName'] = $collectionData[3][0];
+            $input['collectionName'] = $collectionData[2][0];
+        } elseif (preg_match('/^array</', $input['class'])) { //See if a collection directive was attempted. Must be malformed.
+            throw new \InvalidArgumentException(
+                sprintf(
+                    'Malformed collection directive: %s. Proper format is: array<Fully\\Qualified\\ClassName> or array<Fully\\Qualified\\ClassName> as collectionName',
+                    $input['class']
+                )
+            );
         }
 
         // normalize groups
diff --git a/Tests/Extractor/ApiDocExtractorTest.php b/Tests/Extractor/ApiDocExtractorTest.php
index a208b6e..a0dbd29 100644
--- a/Tests/Extractor/ApiDocExtractorTest.php
+++ b/Tests/Extractor/ApiDocExtractorTest.php
@@ -256,43 +256,4 @@ class ApiDocExtractorTest extends WebTestCase
         );
         $this->assertCount(1, $parsers);
     }
-
-    public function testCollectionOutputNormalization()
-    {
-        $extractor = new TestExtractor();
-        $normalized = $extractor->getNormalization('array<Vendor\\Namespace\\Test>');
-
-        $this->assertArrayHasKey('class', $normalized);
-        $this->assertArrayHasKey('collection', $normalized);
-        $this->assertArrayHasKey('collectionName', $normalized);
-
-        $this->assertEquals('Vendor\\Namespace\\Test', $normalized['class']);
-        $this->assertEquals('', $normalized['collectionName']);
-        $this->assertTrue($normalized['collection']);
-
-    }
-
-    public function testNamedCollectionOutputNormalization()
-    {
-        $extractor = new TestExtractor();
-        $normalized = $extractor->getNormalization('array<Vendor\\Namespace\\Test> as    tests');
-
-        $this->assertArrayHasKey('class', $normalized);
-        $this->assertArrayHasKey('collection', $normalized);
-        $this->assertArrayHasKey('collectionName', $normalized);
-
-        $this->assertEquals('Vendor\\Namespace\\Test', $normalized['class']);
-        $this->assertEquals('tests', $normalized['collectionName']);
-        $this->assertTrue($normalized['collection']);
-    }
-
-    public function testFailedCollectionOutputNormalization()
-    {
-        $extractor = new TestExtractor();
-        $normalized = $extractor->getNormalization('array<Vendor\\Test');
-
-        $this->assertArrayNotHasKey('collection', $normalized);
-        $this->assertArrayNotHasKey('collectionName', $normalized);
-
-    }
 }
diff --git a/Tests/Extractor/CollectionDirectiveTest.php b/Tests/Extractor/CollectionDirectiveTest.php
new file mode 100644
index 0000000..c432726
--- /dev/null
+++ b/Tests/Extractor/CollectionDirectiveTest.php
@@ -0,0 +1,109 @@
+<?php
+
+
+namespace Nelmio\ApiDocBundle\Tests\Extractor;
+
+class CollectionDirectiveTest extends \PHPUnit_Framework_TestCase
+{
+    /**
+     * @var TestExtractor
+     */
+    private $testExtractor;
+
+    public function setUp()
+    {
+        $this->testExtractor = new TestExtractor();
+    }
+
+    private function normalize($input)
+    {
+        return $this->testExtractor->getNormalization($input);
+    }
+
+    /**
+     * @dataProvider dataNormalizationTests
+     */
+    public function testNormalizations($input, callable $callable)
+    {
+          call_user_func($callable, $this->normalize($input), $this);
+    }
+
+    public function dataNormalizationTests()
+    {
+        return array(
+            'test_simple_notation' => array(
+                'array<User>',
+                function ($actual, \PHPUnit_Framework_TestCase $case) {
+                    $case->assertArrayHasKey('collection', $actual);
+                    $case->assertArrayHasKey('collectionName', $actual);
+                    $case->assertArrayHasKey('class', $actual);
+
+                    $case->assertTrue($actual['collection']);
+                    $case->assertEquals('', $actual['collectionName']);
+                    $case->assertEquals('User', $actual['class']);
+                }
+            ),
+            'test_simple_notation_with_namespaces' => array(
+                'array<Vendor0_2\\Namespace1\\Namespace_2\\User>',
+                function ($actual, \PHPUnit_Framework_TestCase $case) {
+                    $case->assertArrayHasKey('collection', $actual);
+                    $case->assertArrayHasKey('collectionName', $actual);
+                    $case->assertArrayHasKey('class', $actual);
+
+                    $case->assertTrue($actual['collection']);
+                    $case->assertEquals('', $actual['collectionName']);
+                    $case->assertEquals('Vendor0_2\\Namespace1\\Namespace_2\\User', $actual['class']);
+                }
+            ),
+            'test_simple_named_collections' => array(
+                'array<Group> as groups',
+                function ($actual, \PHPUnit_Framework_TestCase $case) {
+                    $case->assertArrayHasKey('collection', $actual);
+                    $case->assertArrayHasKey('collectionName', $actual);
+                    $case->assertArrayHasKey('class', $actual);
+
+                    $case->assertTrue($actual['collection']);
+                    $case->assertEquals('groups', $actual['collectionName']);
+                    $case->assertEquals('Group', $actual['class']);
+                }
+            ),
+            'test_namespaced_named_collections' => array(
+                'array<Vendor\\Namespace0\\Namespace_2F3\\Group> as groups',
+                function ($actual, \PHPUnit_Framework_TestCase $case) {
+                    $case->assertArrayHasKey('collection', $actual);
+                    $case->assertArrayHasKey('collectionName', $actual);
+                    $case->assertArrayHasKey('class', $actual);
+
+                    $case->assertTrue($actual['collection']);
+                    $case->assertEquals('groups', $actual['collectionName']);
+                    $case->assertEquals('Vendor\\Namespace0\\Namespace_2F3\\Group', $actual['class']);
+                }
+            ),
+
+        );
+    }
+
+    /**
+     * @expectedException \InvalidArgumentException
+     * @dataProvider dataInvalidDirectives
+     * @param $input
+     */
+    public function testInvalidDirectives($input)
+    {
+        $this->normalize($input);
+    }
+
+    public function dataInvalidDirectives()
+    {
+        return array(
+            array('array<>'),
+            array('array<Vendor\\>'),
+            array('array<2Vendor\\>'),
+            array('array<_Vendor\\>'),
+            array('array<Vendor\\_Class>'),
+            array('array<Vendor\\2Class>'),
+            array('array<User> as'),
+            array('array<User> as '),
+        );
+    }
+}