diff --git a/src/Composer/Autoload/ClassMapGenerator.php b/src/Composer/Autoload/ClassMapGenerator.php
index 09bbd447f..7a19b8345 100644
--- a/src/Composer/Autoload/ClassMapGenerator.php
+++ b/src/Composer/Autoload/ClassMapGenerator.php
@@ -110,8 +110,7 @@ class ClassMapGenerator
 
             foreach ($classes as $class) {
                 // skip classes not within the given namespace prefix
-                // TODO enable in Composer v1.11 or 2.0 whichever comes first
-                if (/* null === $autoloadType && */ null !== $namespace && '' !== $namespace && 0 !== strpos($class, $namespace)) {
+                if (null === $autoloadType && null !== $namespace && '' !== $namespace && 0 !== strpos($class, $namespace)) {
                     continue;
                 }
 
@@ -180,19 +179,15 @@ class ClassMapGenerator
         // warn only if no valid classes, else silently skip invalid
         if (empty($validClasses)) {
             foreach ($rejectedClasses as $class) {
-                trigger_error(
-                    "Class $class located in ".preg_replace('{^'.preg_quote(getcwd()).'}', '.', $filePath, 1)." does not comply with $namespaceType autoloading standard. It will not autoload anymore in Composer v2.0.",
-                    E_USER_DEPRECATED
-                );
+                if ($io) {
+                    $io->writeError("<warning>Class $class located in ".preg_replace('{^'.preg_quote(getcwd()).'}', '.', $filePath, 1)." does not comply with $namespaceType autoloading standard. Skipping.</warning>");
+                }
             }
 
-            // TODO enable in Composer 2.0
-            //return array();
+            return array();
         }
 
-        // TODO enable in Composer 2.0 & unskip test in AutoloadGeneratorTest::testPSRToClassMapIgnoresNonPSRClasses
-        //return $validClasses;
-        return $classes;
+        return $validClasses;
     }
 
     /**
diff --git a/tests/Composer/Test/Autoload/AutoloadGeneratorTest.php b/tests/Composer/Test/Autoload/AutoloadGeneratorTest.php
index 3cd8f7ff2..6cb9b76dc 100644
--- a/tests/Composer/Test/Autoload/AutoloadGeneratorTest.php
+++ b/tests/Composer/Test/Autoload/AutoloadGeneratorTest.php
@@ -604,8 +604,6 @@ class AutoloadGeneratorTest extends TestCase
     {
         $package = new Package('a', '1.0', '1.0');
 
-        $this->markTestSkipped('Skipped until ClassMapGenerator ignoring of invalid PSR-x classes is enabled');
-
         $package->setAutoload(array(
             'psr-0' => array('psr0_' => 'psr0/'),
             'psr-4' => array('psr4\\' => 'psr4/'),