diff --git a/composer.json b/composer.json
index 0bedc59..43275fe 100644
--- a/composer.json
+++ b/composer.json
@@ -22,7 +22,7 @@
         "phpstan/phpstan": "1.10.16 || 1.4.10",
         "phpunit/phpunit": "^9.6 || ^7.5",
         "psr/container": "^2 || ^1",
-        "react/promise-timer": "^1.9"
+        "react/promise-timer": "^1.10"
     },
     "autoload": {
         "psr-4": {
diff --git a/src/AccessLogHandler.php b/src/AccessLogHandler.php
index 74052c0..d62016f 100644
--- a/src/AccessLogHandler.php
+++ b/src/AccessLogHandler.php
@@ -37,6 +37,7 @@ public function __invoke(ServerRequestInterface $request, callable $next)
         $response = $next($request);
 
         if ($response instanceof PromiseInterface) {
+            /** @var PromiseInterface<ResponseInterface> $response */
             return $response->then(function (ResponseInterface $response) use ($request, $now) {
                 $this->logWhenClosed($request, $response, $now);
                 return $response;
diff --git a/src/App.php b/src/App.php
index 9fb72c7..c49aa80 100644
--- a/src/App.php
+++ b/src/App.php
@@ -271,6 +271,9 @@ private function handleRequest(ServerRequestInterface $request)
         return $response;
     }
 
+    /**
+     * @return PromiseInterface<ResponseInterface>
+     */
     private function coroutine(\Generator $generator): PromiseInterface
     {
         $next = null;
diff --git a/src/ErrorHandler.php b/src/ErrorHandler.php
index 1035d3f..e26d184 100644
--- a/src/ErrorHandler.php
+++ b/src/ErrorHandler.php
@@ -49,11 +49,12 @@ public function __invoke(ServerRequestInterface $request, callable $next)
                 }
             }, function ($e) {
                 // Promise rejected, always a `\Throwable` as of Promise v3
-                assert($e instanceof \Throwable || !\method_exists(PromiseInterface::class, 'catch'));
+                assert($e instanceof \Throwable || !\method_exists(PromiseInterface::class, 'catch')); // @phpstan-ignore-line
 
                 if ($e instanceof \Throwable) {
                     return $this->errorInvalidException($e);
-                } else {
+                } else { // @phpstan-ignore-line
+                    // @phpstan-ignore-next-line
                     return $this->errorInvalidResponse(\React\Promise\reject($e)); // @codeCoverageIgnore
                 }
             });
diff --git a/src/Io/FiberHandler.php b/src/Io/FiberHandler.php
index 1a36740..07dc713 100644
--- a/src/Io/FiberHandler.php
+++ b/src/Io/FiberHandler.php
@@ -44,8 +44,9 @@ public function __invoke(ServerRequestInterface $request, callable $next)
 
             // if the next request handler returns immediately, the fiber can terminate immediately without using a Deferred
             // if the next request handler suspends the fiber, we only reach this point after resuming the fiber, so the code below will have assigned a Deferred
-            /** @var ?Deferred $deferred */
+            /** @var ?Deferred<ResponseInterface> $deferred */
             if ($deferred !== null) {
+                assert($response instanceof ResponseInterface);
                 $deferred->resolve($response);
             }
 
@@ -56,7 +57,7 @@ public function __invoke(ServerRequestInterface $request, callable $next)
         $fiber->start();
         if ($fiber->isTerminated()) {
             /** @throws void because fiber is known to have terminated successfully */
-            /** @var ResponseInterface|PromiseInterface|\Generator */
+            /** @var ResponseInterface|PromiseInterface<ResponseInterface>|\Generator */
             return $fiber->getReturn();
         }
 
diff --git a/src/Io/SapiHandler.php b/src/Io/SapiHandler.php
index 918a62f..d3faf27 100644
--- a/src/Io/SapiHandler.php
+++ b/src/Io/SapiHandler.php
@@ -34,6 +34,7 @@ public function run(callable $handler): void
         if ($response instanceof ResponseInterface) {
             $this->sendResponse($response);
         } elseif ($response instanceof PromiseInterface) {
+            /** @var PromiseInterface<ResponseInterface> $response */
             $response->then(function (ResponseInterface $response): void {
                 $this->sendResponse($response);
             });
diff --git a/tests/AppMiddlewareTest.php b/tests/AppMiddlewareTest.php
index d0ec78d..5fcc067 100644
--- a/tests/AppMiddlewareTest.php
+++ b/tests/AppMiddlewareTest.php
@@ -280,6 +280,7 @@ public function testMiddlewareCallsNextReturnsDeferredResponseModifiedInMiddlewa
         $middleware = function (ServerRequestInterface $request, callable $next) {
             $promise = $next($request);
             assert($promise instanceof PromiseInterface);
+            /** @var PromiseInterface<ResponseInterface> $promise */
 
             return $promise->then(function (ResponseInterface $response) {
                 return $response->withHeader('Content-Type', 'text/html');
@@ -303,7 +304,7 @@ public function testMiddlewareCallsNextReturnsDeferredResponseModifiedInMiddlewa
         $ref->setAccessible(true);
         $promise = $ref->invoke($app, $request);
 
-        /** @var PromiseInterface $promise */
+        /** @var PromiseInterface<ResponseInterface> $promise */
         $this->assertInstanceOf(PromiseInterface::class, $promise);
 
         $response = null;
@@ -350,7 +351,7 @@ public function testMiddlewareCallsNextReturnsCoroutineResponseModifiedInMiddlew
         $ref->setAccessible(true);
         $promise = $ref->invoke($app, $request);
 
-        /** @var PromiseInterface $promise */
+        /** @var PromiseInterface<ResponseInterface> $promise */
         $this->assertInstanceOf(PromiseInterface::class, $promise);
 
         $response = null;
@@ -680,7 +681,7 @@ public function testGlobalMiddlewareReturnsPromiseWhichResolvesWithResponseWitho
         $ref->setAccessible(true);
         $promise = $ref->invoke($app, $request);
 
-        /** @var PromiseInterface $promise */
+        /** @var PromiseInterface<ResponseInterface> $promise */
         $this->assertInstanceOf(PromiseInterface::class, $promise);
 
         $response = null;
@@ -720,7 +721,7 @@ public function testGlobalMiddlewareCallsNextReturnsPromiseWhichResolvesWithModi
         $ref->setAccessible(true);
         $promise = $ref->invoke($app, $request);
 
-        /** @var PromiseInterface $promise */
+        /** @var PromiseInterface<ResponseInterface> $promise */
         $this->assertInstanceOf(PromiseInterface::class, $promise);
 
         $response = null;
@@ -764,7 +765,7 @@ public function testGlobalMiddlewareCallsNextReturnsPromiseWhichResolvesWithModi
         $ref->setAccessible(true);
         $promise = $ref->invoke($app, $request);
 
-        /** @var PromiseInterface $promise */
+        /** @var PromiseInterface<ResponseInterface> $promise */
         $this->assertInstanceOf(PromiseInterface::class, $promise);
 
         $response = null;
diff --git a/tests/AppTest.php b/tests/AppTest.php
index b5e1411..43679f5 100644
--- a/tests/AppTest.php
+++ b/tests/AppTest.php
@@ -1052,7 +1052,7 @@ public function testHandleRequestWithMatchingRouteReturnsPromiseWhichFulfillsWit
         $ref->setAccessible(true);
         $promise = $ref->invoke($app, $request);
 
-        /** @var PromiseInterface $promise */
+        /** @var PromiseInterface<ResponseInterface> $promise */
         $this->assertInstanceOf(PromiseInterface::class, $promise);
 
         $response = null;
@@ -1082,7 +1082,7 @@ public function testHandleRequestWithMatchingRouteReturnsPendingPromiseWhenHandl
         $ref->setAccessible(true);
         $promise = $ref->invoke($app, $request);
 
-        /** @var PromiseInterface $promise */
+        /** @var PromiseInterface<ResponseInterface> $promise */
         $this->assertInstanceOf(PromiseInterface::class, $promise);
 
         $resolved = false;
@@ -1150,7 +1150,7 @@ public function testHandleRequestWithMatchingRouteReturnsPromiseWhichFulfillsWit
         $ref->setAccessible(true);
         $promise = $ref->invoke($app, $request);
 
-        /** @var PromiseInterface $promise */
+        /** @var PromiseInterface<ResponseInterface> $promise */
         $this->assertInstanceOf(PromiseInterface::class, $promise);
 
         $response = null;
@@ -1193,7 +1193,7 @@ public function testHandleRequestWithMatchingRouteReturnsPromiseWhichFulfillsWit
         $ref->setAccessible(true);
         $promise = $ref->invoke($app, $request);
 
-        /** @var PromiseInterface $promise */
+        /** @var PromiseInterface<ResponseInterface> $promise */
         $this->assertInstanceOf(PromiseInterface::class, $promise);
 
         $response = null;
@@ -1223,7 +1223,7 @@ public function testHandleRequestWithMatchingRouteReturnsPendingPromiseWhenHandl
         $ref->setAccessible(true);
         $promise = $ref->invoke($app, $request);
 
-        /** @var PromiseInterface $promise */
+        /** @var PromiseInterface<never> $promise */
         $this->assertInstanceOf(PromiseInterface::class, $promise);
 
         $resolved = false;
@@ -1285,7 +1285,7 @@ public function testHandleRequestWithMatchingRouteReturnsPromiseResolvingWithRes
         $ref->setAccessible(true);
         $promise = $ref->invoke($app, $request);
 
-        /** @var PromiseInterface $promise */
+        /** @var PromiseInterface<ResponseInterface> $promise */
         $this->assertInstanceOf(PromiseInterface::class, $promise);
 
         $response = null;
@@ -1384,7 +1384,7 @@ public function testHandleRequestWithMatchingRouteReturnsPromiseWhichFulfillsWit
         $ref->setAccessible(true);
         $promise = $ref->invoke($app, $request);
 
-        /** @var PromiseInterface $promise */
+        /** @var PromiseInterface<ResponseInterface> $promise */
         $this->assertInstanceOf(PromiseInterface::class, $promise);
 
         $response = null;
@@ -1412,7 +1412,7 @@ public function testHandleRequestWithMatchingRouteReturnsPromiseWhichFulfillsWit
         $app = $this->createAppWithoutLogger();
 
         $app->get('/users', function () {
-            return reject(null);
+            return reject(null); // @phpstan-ignore-line
         });
 
         $request = new ServerRequest('GET', 'http://localhost/users');
@@ -1422,7 +1422,7 @@ public function testHandleRequestWithMatchingRouteReturnsPromiseWhichFulfillsWit
         $ref->setAccessible(true);
         $promise = $ref->invoke($app, $request);
 
-        /** @var PromiseInterface $promise */
+        /** @var PromiseInterface<ResponseInterface> $promise */
         $this->assertInstanceOf(PromiseInterface::class, $promise);
 
         $response = null;
@@ -1457,7 +1457,7 @@ public function testHandleRequestWithMatchingRouteReturnsPromiseWhichFulfillsWit
         $ref->setAccessible(true);
         $promise = $ref->invoke($app, $request);
 
-        /** @var PromiseInterface $promise */
+        /** @var PromiseInterface<ResponseInterface> $promise */
         $this->assertInstanceOf(PromiseInterface::class, $promise);
 
         $response = null;
@@ -1523,7 +1523,7 @@ public function testHandleRequestWithMatchingRouteReturnsPromiseWhichFulfillsWit
         $ref->setAccessible(true);
         $promise = $ref->invoke($app, $request);
 
-        /** @var PromiseInterface $promise */
+        /** @var PromiseInterface<ResponseInterface> $promise */
         $this->assertInstanceOf(PromiseInterface::class, $promise);
 
         $response = null;
@@ -1593,7 +1593,7 @@ public function testHandleRequestWithMatchingRouteReturnsPromiseWhichFulfillsWit
         $ref->setAccessible(true);
         $promise = $ref->invoke($app, $request);
 
-        /** @var PromiseInterface $promise */
+        /** @var PromiseInterface<ResponseInterface> $promise */
         $this->assertInstanceOf(PromiseInterface::class, $promise);
 
         $response = null;
@@ -1632,7 +1632,7 @@ public function testHandleRequestWithMatchingRouteReturnsPromiseWhichFulfillsWit
         $ref->setAccessible(true);
         $promise = $ref->invoke($app, $request);
 
-        /** @var PromiseInterface $promise */
+        /** @var PromiseInterface<ResponseInterface> $promise */
         $this->assertInstanceOf(PromiseInterface::class, $promise);
 
         $response = null;
@@ -1889,7 +1889,7 @@ public function testHandleRequestWithMatchingRouteReturnsPromiseWhichFulfillsWit
         $ref->setAccessible(true);
         $promise = $ref->invoke($app, $request);
 
-        /** @var PromiseInterface $promise */
+        /** @var PromiseInterface<ResponseInterface> $promise */
         $this->assertInstanceOf(PromiseInterface::class, $promise);
 
         $response = null;
@@ -1924,7 +1924,7 @@ public function testHandleRequestWithMatchingRouteReturnsInternalServerErrorResp
         $ref->setAccessible(true);
         $promise = $ref->invoke($app, $request);
 
-        /** @var PromiseInterface $promise */
+        /** @var PromiseInterface<ResponseInterface> $promise */
         $this->assertInstanceOf(PromiseInterface::class, $promise);
 
         $response = null;
diff --git a/tests/ErrorHandlerTest.php b/tests/ErrorHandlerTest.php
index 905c1e8..96fb02a 100644
--- a/tests/ErrorHandlerTest.php
+++ b/tests/ErrorHandlerTest.php
@@ -34,7 +34,7 @@ public function testInvokeWithHandlerReturningPromiseResolvingWithResponseReturn
 
         $promise = $handler($request, function () use ($response) { return resolve($response); });
 
-        /** @var PromiseInterface $promise */
+        /** @var PromiseInterface<ResponseInterface> $promise */
         $this->assertInstanceOf(PromiseInterface::class, $promise);
 
         $ret = null;
@@ -106,7 +106,7 @@ public function testInvokeWithHandlerReturningGeneratorYieldingRejectedPromiseIn
         $this->assertInstanceOf(\Generator::class, $generator);
         $promise = $generator->current();
 
-        /** @var PromiseInterface $promise */
+        /** @var PromiseInterface<never> $promise */
         $this->assertInstanceOf(PromiseInterface::class, $promise);
         $e = null;
         $promise->then(null, function ($reason) use (&$e) {
@@ -146,7 +146,7 @@ public function testInvokeWithHandlerReturningPromiseRejectingWithExceptionRetur
             return reject(new \RuntimeException());
         });
 
-        /** @var PromiseInterface $promise */
+        /** @var PromiseInterface<ResponseInterface> $promise */
         $this->assertInstanceOf(PromiseInterface::class, $promise);
 
         $response = null;
@@ -216,7 +216,7 @@ public function testInvokeWithHandlerReturningGeneratorYieldingPromiseRejectingW
         $this->assertInstanceOf(\Generator::class, $generator);
         $promise = $generator->current();
 
-        /** @var PromiseInterface $promise */
+        /** @var PromiseInterface<never> $promise */
         $this->assertInstanceOf(PromiseInterface::class, $promise);
         $e = null;
         $promise->then(null, function ($reason) use (&$e) {
@@ -258,7 +258,7 @@ public function testInvokeWithHandlerReturningPromiseResolvingWithNullReturnsPro
             return resolve(null);
         });
 
-        /** @var PromiseInterface $promise */
+        /** @var PromiseInterface<ResponseInterface> $promise */
         $this->assertInstanceOf(PromiseInterface::class, $promise);
 
         $response = null;
@@ -282,10 +282,10 @@ public function testInvokeWithHandlerReturningPromiseRejectingWithNullReturnsPro
         $request = new ServerRequest('GET', 'http://example.com/');
 
         $promise = $handler($request, function () {
-            return reject(null);
+            return reject(null); // @phpstan-ignore-line
         });
 
-        /** @var PromiseInterface $promise */
+        /** @var PromiseInterface<ResponseInterface> $promise */
         $this->assertInstanceOf(PromiseInterface::class, $promise);
 
         $response = null;
diff --git a/tests/Io/FiberHandlerTest.php b/tests/Io/FiberHandlerTest.php
index a552a09..cb354f7 100644
--- a/tests/Io/FiberHandlerTest.php
+++ b/tests/Io/FiberHandlerTest.php
@@ -35,7 +35,7 @@ public function testInvokeWithHandlerReturningPromiseResolvingWithResponseReturn
 
         $promise = $handler($request, function () use ($response) { return resolve($response); });
 
-        /** @var PromiseInterface $promise */
+        /** @var PromiseInterface<Response> $promise */
         $this->assertInstanceOf(PromiseInterface::class, $promise);
 
         $ret = null;
@@ -157,7 +157,7 @@ public function testInvokeWithHandlerReturningResponseAfterAwaitingPendingPromis
             return await($deferred->promise());
         });
 
-        /** @var PromiseInterface $promise */
+        /** @var PromiseInterface<Response> $promise */
         $this->assertInstanceOf(PromiseInterface::class, $promise);
 
         $ret = null;
diff --git a/tests/Io/ReactiveHandlerTest.php b/tests/Io/ReactiveHandlerTest.php
index d9b43fb..70e63a5 100644
--- a/tests/Io/ReactiveHandlerTest.php
+++ b/tests/Io/ReactiveHandlerTest.php
@@ -156,7 +156,10 @@ public function testRunWillListenForHttpRequestAndSendBackHttpResponseOverSocket
 
         Loop::futureTick(function () use ($addr): void {
             $connector = new Connector();
-            $connector->connect($addr)->then(function (ConnectionInterface $connection): void {
+            $promise = $connector->connect($addr);
+
+            /** @var \React\Promise\PromiseInterface<ConnectionInterface> $promise */
+            $promise->then(function (ConnectionInterface $connection): void {
                 $connection->on('data', function (string $data): void {
                     $this->assertEquals("HTTP/1.0 200 OK\r\nContent-Length: 3\r\n\r\nOK\n", $data);
                 });
@@ -203,7 +206,10 @@ public function testRunWillReportHttpErrorForInvalidClientRequest(): void
 
         Loop::futureTick(function () use ($addr, $logger): void {
             $connector = new Connector();
-            $connector->connect($addr)->then(function (ConnectionInterface $connection) use ($logger): void {
+            $promise = $connector->connect($addr);
+
+            /** @var \React\Promise\PromiseInterface<ConnectionInterface> $promise */
+            $promise->then(function (ConnectionInterface $connection) use ($logger): void {
                 $logger->expects($this->once())->method('log')->with($this->matchesRegularExpression('/^HTTP error: .*$/'));
                 $connection->write("not a valid HTTP request\r\n\r\n");
 
diff --git a/tests/install-as-dep/composer.json b/tests/install-as-dep/composer.json
index d003086..45c2243 100644
--- a/tests/install-as-dep/composer.json
+++ b/tests/install-as-dep/composer.json
@@ -1,7 +1,7 @@
 {
     "require": {
         "clue/framework-x": "*@dev",
-        "react/promise-timer": "^1.9"
+        "react/promise-timer": "^1.10"
     },
     "repositories": [
         {