diff --git a/README.md b/README.md
index 2d26424..c6f0b60 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,6 @@
 # Nazg Micro Framework Core Repository
 
-[![Packagist](https://img.shields.io/badge/HHVM-%3E=4.35-orange.svg?style=flat-square)](https://packagist.org/packages/nazg/framework)
+[![Packagist](https://img.shields.io/badge/HHVM-%3E=4.41-orange.svg?style=flat-square)](https://packagist.org/packages/nazg/framework)
 [![Packagist](https://img.shields.io/packagist/l/nazg/framework.svg?style=flat-square)](https://packagist.org/packages/nazg/framework)
 [![Build Status](http://img.shields.io/travis/nazg-hack/framework/master.svg?style=flat-square)](https://travis-ci.org/nazg-hack/framework)
 
@@ -8,7 +8,7 @@ Http Application / MicroFramework for HHVM/Hack
 
 ## Supported
 
-HHVM 4.35 and above.
+HHVM 4.41 and above.
 
 ## Usage
 
diff --git a/composer.json b/composer.json
index 5037554..56ed7ba 100644
--- a/composer.json
+++ b/composer.json
@@ -16,22 +16,20 @@
     }
   ],
   "require": {
-    "hhvm": "^4.35",
+    "hhvm": "^4.41",
     "hhvm/hsl": "^4.0",
-    "hhvm/hsl-experimental": "^4.25",
+    "hhvm/hsl-experimental": "^4.50",
     "hhvm/hhvm-autoload": "^3.0",
-    "hhvm/type-assert": "^3.7",
-    "hack-psr/psr7-http-message-hhi": "^1.0.0",
-    "ytake/hungrr": "^0.9.0",
+    "ytake/hungrr": "^0.10.0",
     "ytake/hhypermedia": "^0.5.0",
-    "nazg/glue": "^1.4.0",
-    "nazg/heredity": "^1.9",
+    "nazg/glue": "^1.4",
+    "nazg/heredity": "^1.10.0",
     "nazg/hcache": "^0.5.0",
-    "nazg/http-server-request-handler": "^0.5",
-    "nazg/http-executor": "^0.9",
-    "facebook/hack-router": ">=0.17 <1.0",
-    "facebook/hack-http-request-response-interfaces": "^0.2",
-    "hack-logging/hack-logging": "^0.4.0"
+    "nazg/http-server-request-handler": "^0.6.0",
+    "nazg/http-executor": "^0.10.0",
+    "facebook/hack-router": "^0.19.6",
+    "facebook/hack-http-request-response-interfaces": "^0.3",
+    "hack-logging/hack-logging": "^0.5.0"
   },
   "require-dev": {
     "facebook/fbexpect": "^2.6.1",
diff --git a/src/Exception/ExceptionHandler.hack b/src/Exception/ExceptionHandler.hack
index 4a84791..abc1944 100644
--- a/src/Exception/ExceptionHandler.hack
+++ b/src/Exception/ExceptionHandler.hack
@@ -20,8 +20,7 @@ use type Nazg\HttpExecutor\Emitter\EmitterInterface;
 use type Facebook\Experimental\Http\Message\ResponseInterface;
 use type Facebook\Experimental\Http\Message\UriInterface;
 use type Ytake\Hungrr\StatusCode;
-use namespace HH\Lib\{Dict, C};
-use namespace HH\Lib\Experimental\IO;
+use namespace HH\Lib\{Dict, C, IO};
 use function get_class;
 use function is_array;
 use function json_encode;
diff --git a/src/Exception/ExceptionHandlerProvider.hack b/src/Exception/ExceptionHandlerProvider.hack
index 7e745b1..0af5eab 100644
--- a/src/Exception/ExceptionHandlerProvider.hack
+++ b/src/Exception/ExceptionHandlerProvider.hack
@@ -18,7 +18,7 @@ namespace Nazg\Exception;
 use type Nazg\Glue\Container;
 use type Nazg\Glue\ProviderInterface;
 use type Nazg\HttpExecutor\Emitter\EmitterInterface;
-use namespace HH\Lib\Experimental\IO;
+use namespace HH\Lib\IO;
 
 class ExceptionHandlerProvider implements ProviderInterface<ExceptionHandleInterface> {
 
diff --git a/src/Foundation/Application.hack b/src/Foundation/Application.hack
index 5d7ae6f..263260f 100644
--- a/src/Foundation/Application.hack
+++ b/src/Foundation/Application.hack
@@ -26,7 +26,7 @@ use type Nazg\Glue\Container;
 use type Nazg\HttpExecutor\AsyncRequestHandleExecutor;
 
 use namespace Nazg\HttpExecutor\Emitter;
-use namespace HH\Lib\Experimental\IO;
+use namespace HH\Lib\IO;
 use namespace Nazg\Middleware;
 use namespace HH\Lib\Vec;
 
diff --git a/src/Foundation/ApplicationProvider.hack b/src/Foundation/ApplicationProvider.hack
index 2bf401c..8741473 100644
--- a/src/Foundation/ApplicationProvider.hack
+++ b/src/Foundation/ApplicationProvider.hack
@@ -23,7 +23,7 @@ use type HackLogging\Logger;
 use namespace Nazg\Logger;
 use namespace Nazg\Exception;
 use namespace Nazg\HttpExecutor\Emitter;
-use namespace HH\Lib\Experimental\IO;
+use namespace HH\Lib\IO;
 
 final class ApplicationProvider extends ServiceProvider {
 
diff --git a/src/Http/VndErrorResponse.hack b/src/Http/VndErrorResponse.hack
index 744a6ad..2571fe8 100644
--- a/src/Http/VndErrorResponse.hack
+++ b/src/Http/VndErrorResponse.hack
@@ -18,7 +18,7 @@ namespace Nazg\Http;
 use type Ytake\Hungrr\Response\JsonResponse;
 use type Ytake\Hungrr\StatusCode;
 use type Ytake\Hungrr\Response\InjectContentTypeTrait;
-use namespace HH\Lib\Experimental\IO;
+use namespace HH\Lib\IO;
 
 final class VndErrorResponse extends JsonResponse {
 
diff --git a/src/Logger/LoggerProvider.hack b/src/Logger/LoggerProvider.hack
index f0d5e52..79f9c37 100644
--- a/src/Logger/LoggerProvider.hack
+++ b/src/Logger/LoggerProvider.hack
@@ -20,7 +20,7 @@ use type Nazg\Glue\ProviderInterface;
 use type Nazg\Foundation\ApplicationConfig;
 use type HackLogging\Logger;
 use type HackLogging\Handler\FilesystemHandler;
-use namespace HH\Lib\Experimental\File;
+use namespace HH\Lib\File;
 
 final class LoggerProvider implements ProviderInterface<Logger> {
 
diff --git a/src/Middleware/Dispatcher.hack b/src/Middleware/Dispatcher.hack
index 2e941c0..6f65acf 100644
--- a/src/Middleware/Dispatcher.hack
+++ b/src/Middleware/Dispatcher.hack
@@ -15,7 +15,7 @@
  */
  namespace Nazg\Middleware;
 
-use type HH\Lib\Experimental\IO\CloseableWriteHandle;
+use type HH\Lib\IO\CloseableWriteHandle;
 use type Nazg\Heredity\AsyncHeredity;
 use type Nazg\Glue\Container;
 use type Nazg\Http\Server\AsyncMiddlewareInterface;
diff --git a/src/Middleware/LogExceptionMiddleware.hack b/src/Middleware/LogExceptionMiddleware.hack
index 0d7449b..a5a97a4 100644
--- a/src/Middleware/LogExceptionMiddleware.hack
+++ b/src/Middleware/LogExceptionMiddleware.hack
@@ -17,7 +17,7 @@ namespace Nazg\Middleware;
 
 use type HackLogging\Logger;
 use type HackLogging\LogLevel;
-use type HH\Lib\Experimental\IO\CloseableWriteHandle;
+use type HH\Lib\IO\CloseableWriteHandle;
 use type Facebook\Experimental\Http\Message\ResponseInterface;
 use type Facebook\Experimental\Http\Message\ServerRequestInterface;
 use type Nazg\Http\Server\AsyncMiddlewareInterface;
diff --git a/src/Middleware/SimpleCorsMiddleware.hack b/src/Middleware/SimpleCorsMiddleware.hack
index d9b50b4..e11b086 100644
--- a/src/Middleware/SimpleCorsMiddleware.hack
+++ b/src/Middleware/SimpleCorsMiddleware.hack
@@ -18,7 +18,7 @@ namespace Nazg\Middleware;
 use type Facebook\HackRouter\HttpMethod;
 use type Facebook\Experimental\Http\Message\ResponseInterface;
 use type Facebook\Experimental\Http\Message\ServerRequestInterface;
-use type HH\Lib\Experimental\IO\CloseableWriteHandle;
+use type HH\Lib\IO\CloseableWriteHandle;
 use type Nazg\Http\Server\AsyncMiddlewareInterface;
 use type Nazg\Http\Server\AsyncRequestHandlerInterface;
 use function implode;
diff --git a/src/RequestHandler/AsyncFallbackHandler.hack b/src/RequestHandler/AsyncFallbackHandler.hack
index 64100b4..bfe9df4 100644
--- a/src/RequestHandler/AsyncFallbackHandler.hack
+++ b/src/RequestHandler/AsyncFallbackHandler.hack
@@ -15,7 +15,7 @@
  */
 namespace Nazg\RequestHandler;
 
-use type HH\Lib\Experimental\IO\WriteHandle;
+use type HH\Lib\IO\WriteHandle;
 use type Facebook\Experimental\Http\Message\ResponseInterface;
 use type Facebook\Experimental\Http\Message\ServerRequestInterface;
 use type Nazg\Http\Server\AsyncRequestHandlerInterface;
diff --git a/tests/ApplicationTest.hack b/tests/ApplicationTest.hack
index fc6dc3a..9b160ea 100644
--- a/tests/ApplicationTest.hack
+++ b/tests/ApplicationTest.hack
@@ -2,7 +2,7 @@ use type Facebook\HackTest\HackTest;
 use type Nazg\Glue\{Container, DependencyFactory};
 use type Ytake\Hungrr\ServerRequestFactory;
 use type Facebook\Experimental\Http\Message\HTTPMethod;
-use namespace HH\Lib\Experimental\IO;
+use namespace HH\Lib\IO;
 use namespace Nazg\Foundation;
 use function Facebook\FBExpect\expect;
 
diff --git a/tests/Exception/ExceptionHandlerTest.hack b/tests/Exception/ExceptionHandlerTest.hack
index acc851b..e752ba0 100644
--- a/tests/Exception/ExceptionHandlerTest.hack
+++ b/tests/Exception/ExceptionHandlerTest.hack
@@ -6,7 +6,7 @@ use type Nazg\Exception\ExceptionHandler;
 use type Nazg\Exception\ExceptionRegister;
 use type Nazg\Exception\ExceptionHandlerProvider;
 use type Nazg\Exception\NotFoundHttpException;
-use namespace HH\Lib\Experimental\IO;
+use namespace HH\Lib\IO;
 use namespace Nazg\HttpExecutor\Emitter;
 
 final class ExceptionHandlerTest extends HackTest {
diff --git a/tests/Http/VndErrorResponseTest.hack b/tests/Http/VndErrorResponseTest.hack
index 816862f..9c8a779 100644
--- a/tests/Http/VndErrorResponseTest.hack
+++ b/tests/Http/VndErrorResponseTest.hack
@@ -1,7 +1,7 @@
 use type Nazg\Http\VndErrorResponse;
 use type Ytake\Hungrr\StatusCode;
 use type Facebook\HackTest\HackTest;
-use namespace HH\Lib\Experimental\IO;
+use namespace HH\Lib\IO;
 use function Facebook\FBExpect\expect;
 
 final class VndErrorResponseTest extends HackTest {
diff --git a/tests/Logger/LoggerProviderTest.hack b/tests/Logger/LoggerProviderTest.hack
index 09fb3d9..95ae06f 100644
--- a/tests/Logger/LoggerProviderTest.hack
+++ b/tests/Logger/LoggerProviderTest.hack
@@ -3,7 +3,7 @@ use type Nazg\Glue\{Container, DependencyFactory};
 use type Nazg\Foundation\ApplicationConfig;
 use type HackLogging\Logger;
 use type Facebook\HackTest\HackTest;
-use namespace HH\Lib\Experimental\File;
+use namespace HH\Lib\File;
 use function Facebook\FBExpect\expect;
 
 final class LoggerProviderTest extends HackTest {
@@ -14,7 +14,7 @@ final class LoggerProviderTest extends HackTest {
     $container->bind(ApplicationConfig::class)
       ->to(ApplicationConfig::class);
     expect(() ==> $logger->get($container))
-      ->toThrow(\HH\Lib\Experimental\OS\Exception::class);
+      ->toThrow(\HH\Lib\OS\Exception::class);
   }
 
   public function testShouldReturnLoggerInstance(): void {
diff --git a/tests/Middleware/FakeActionMiddleware.hack b/tests/Middleware/FakeActionMiddleware.hack
index de19148..82319ad 100644
--- a/tests/Middleware/FakeActionMiddleware.hack
+++ b/tests/Middleware/FakeActionMiddleware.hack
@@ -1,4 +1,4 @@
-use type HH\Lib\Experimental\IO\CloseableWriteHandle;
+use type HH\Lib\IO\CloseableWriteHandle;
 use type Facebook\Experimental\Http\Message\ResponseInterface;
 use type Facebook\Experimental\Http\Message\ServerRequestInterface;
 use type Nazg\Http\Server\AsyncMiddlewareInterface;
diff --git a/tests/Middleware/FakeThrowExceptionMiddleware.hack b/tests/Middleware/FakeThrowExceptionMiddleware.hack
index 61a9a80..07ca672 100644
--- a/tests/Middleware/FakeThrowExceptionMiddleware.hack
+++ b/tests/Middleware/FakeThrowExceptionMiddleware.hack
@@ -1,4 +1,4 @@
-use type HH\Lib\Experimental\IO\CloseableWriteHandle;
+use type HH\Lib\IO\CloseableWriteHandle;
 use type Facebook\Experimental\Http\Message\ResponseInterface;
 use type Facebook\Experimental\Http\Message\ServerRequestInterface;
 use type Nazg\Http\Server\AsyncMiddlewareInterface;
diff --git a/tests/Middleware/LogExceptionMiddlewareTest.hack b/tests/Middleware/LogExceptionMiddlewareTest.hack
index 4323183..d4559a5 100644
--- a/tests/Middleware/LogExceptionMiddlewareTest.hack
+++ b/tests/Middleware/LogExceptionMiddlewareTest.hack
@@ -7,7 +7,7 @@ use type Nazg\RequestHandler\AsyncFallbackHandler;
 use type Nazg\Foundation\ApplicationConfig;
 use namespace Nazg\Logger;
 use namespace Nazg\Middleware;
-use namespace HH\Lib\Experimental\IO;
+use namespace HH\Lib\IO;
 use function Facebook\FBExpect\expect;
 
 final class LogExceptionMiddlewareTest extends HackTest {
diff --git a/tests/Middleware/SimpleCorsMiddlewareTest.hack b/tests/Middleware/SimpleCorsMiddlewareTest.hack
index 7eebd8a..30bf869 100644
--- a/tests/Middleware/SimpleCorsMiddlewareTest.hack
+++ b/tests/Middleware/SimpleCorsMiddlewareTest.hack
@@ -7,7 +7,7 @@ use type Nazg\RequestHandler\AsyncFallbackHandler;
 use type Nazg\Foundation\ApplicationConfig;
 use namespace Nazg\Logger;
 use namespace Nazg\Middleware;
-use namespace HH\Lib\Experimental\IO;
+use namespace HH\Lib\IO;
 use function Facebook\FBExpect\expect;
 
 final class SimpleCorsMiddlewareTest extends HackTest {
diff --git a/tests/Routing/RouterTest.hack b/tests/Routing/RouterTest.hack
index 373b36b..0b95e14 100644
--- a/tests/Routing/RouterTest.hack
+++ b/tests/Routing/RouterTest.hack
@@ -5,7 +5,7 @@ use type Ytake\Hungrr\ServerRequestFactory;
 use type Facebook\Experimental\Http\Message\HTTPMethod;
 use type Facebook\HackRouter\BaseRouter;
 
-use namespace HH\Lib\Experimental\IO;
+use namespace HH\Lib\IO;
 
 use function Facebook\FBExpect\expect;
 
diff --git a/tests/Validation/ValidatorTest.hack b/tests/Validation/ValidatorTest.hack
index af9bc68..60d61e8 100644
--- a/tests/Validation/ValidatorTest.hack
+++ b/tests/Validation/ValidatorTest.hack
@@ -3,7 +3,7 @@ use type Nazg\Validation\ValidationException;
 use type Facebook\HackTest\HackTest;
 use type Ytake\Hungrr\ServerRequestFactory;
 use namespace Facebook\TypeAssert;
-use namespace HH\Lib\Experimental\IO;
+use namespace HH\Lib\IO;
 use function Facebook\FBExpect\expect;
 
 class ValidatorTest extends HackTest {