diff --git a/.github/workflows/test-unit.yml b/.github/workflows/test-unit.yml
index 0e9e3debee..4262066fdb 100644
--- a/.github/workflows/test-unit.yml
+++ b/.github/workflows/test-unit.yml
@@ -79,13 +79,13 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        php: ['7.4', '8.0', '8.1', '8.2']
+        php: ['7.4', '8.0', '8.1', '8.2', '8.3']
         type: ['Phpunit', 'Phpunit Lowest']
         include:
           - php: 'latest'
             type: 'Phpunit Burn'
     env:
-      LOG_COVERAGE: "${{ fromJSON('{true: \"1\", false: \"\"}')[matrix.php == '8.0' && matrix.type == 'Phpunit' && (github.event_name == 'pull_request' || (github.event_name == 'push' && (github.ref == 'refs/heads/develop' || github.ref == 'refs/heads/master')))] }}"
+      LOG_COVERAGE: "${{ fromJSON('{true: \"1\", false: \"\"}')[matrix.php == '8.2' && matrix.type == 'Phpunit' && (github.event_name == 'pull_request' || (github.event_name == 'push' && (github.ref == 'refs/heads/develop' || github.ref == 'refs/heads/master')))] }}"
     services:
       mysql:
         image: mysql:8
@@ -136,7 +136,7 @@ jobs:
           if [ "${{ matrix.type }}" != "Phpunit" ] && [ "${{ matrix.type }}" != "Phpunit Lowest" ] && [ "${{ matrix.type }}" != "Phpunit Burn" ]; then composer remove --no-interaction --no-update phpunit/phpunit johnkary/phpunit-speedtrap --dev; fi
           if [ "${{ matrix.type }}" != "CodingStyle" ]; then composer remove --no-interaction --no-update friendsofphp/php-cs-fixer --dev; fi
           if [ "${{ matrix.type }}" != "StaticAnalysis" ]; then composer remove --no-interaction --no-update phpstan/\* behat/\* --dev; fi
-          if [ -n "$LOG_COVERAGE" ]; then composer require --no-interaction --no-update phpunit/phpcov; fi
+          if [ -n "$LOG_COVERAGE" ]; then composer require --no-interaction --no-install phpunit/phpcov; fi
           composer update --ansi --prefer-dist --no-interaction --no-progress --optimize-autoloader
           if [ "${{ matrix.type }}" = "Phpunit Lowest" ]; then composer update --ansi --prefer-dist --prefer-lowest --prefer-stable --no-interaction --no-progress --optimize-autoloader; fi
           if [ "${{ matrix.type }}" = "Phpunit Burn" ]; then sed -i 's~ *public function runBare(): void~public function runBare(): void { gc_collect_cycles(); gc_collect_cycles(); $memDiffs = array_fill(0, '"$(if [ \"$GITHUB_EVENT_NAME\" == \"schedule\" ]; then echo 64; else echo 16; fi)"', 0); for ($i = -1; $i < count($memDiffs); ++$i) { $this->_runBare(); gc_collect_cycles(); gc_collect_cycles(); $mem = memory_get_usage(); if ($i !== -1) { $memDiffs[$i] = $mem - $memPrev; } $memPrev = $mem; rsort($memDiffs); if (array_sum($memDiffs) >= 4096 * 1024 || $memDiffs[2] > 0) { $this->onNotSuccessfulTest(new AssertionFailedError( "Memory leak detected! (" . implode(" + ", array_map(fn ($v) => number_format($v / 1024, 3, ".", " "), array_filter($memDiffs))) . " KB, " . ($i + 2) . " iterations)" )); } } } private function _runBare(): void~' vendor/phpunit/phpunit/src/Framework/TestCase.php && cat vendor/phpunit/phpunit/src/Framework/TestCase.php | grep '_runBare('; fi
@@ -238,7 +238,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        php: ['7.4', '8.0', '8.1', '8.2']
+        php: ['7.4', '8.0', '8.1', '8.2', '8.3']
         type: ['Chrome', 'Chrome Lowest']
         include:
           - php: 'latest'
@@ -246,7 +246,7 @@ jobs:
           - php: 'latest'
             type: 'Chrome Slow'
     env:
-      LOG_COVERAGE: "${{ fromJSON('{true: \"1\", false: \"\"}')[matrix.php == '8.0' && matrix.type == 'Chrome' && (github.event_name == 'pull_request' || (github.event_name == 'push' && (github.ref == 'refs/heads/develop' || github.ref == 'refs/heads/master')))] }}"
+      LOG_COVERAGE: "${{ fromJSON('{true: \"1\", false: \"\"}')[matrix.php == '8.2' && matrix.type == 'Chrome' && (github.event_name == 'pull_request' || (github.event_name == 'push' && (github.ref == 'refs/heads/develop' || github.ref == 'refs/heads/master')))] }}"
     services:
       mysql:
         image: mysql:8
@@ -353,7 +353,7 @@ jobs:
           composer remove --no-interaction --no-update phpunit/phpunit johnkary/phpunit-speedtrap --dev
           composer remove --no-interaction --no-update friendsofphp/php-cs-fixer --dev
           composer remove --no-interaction --no-update phpstan/\* --dev
-          if [ -n "$LOG_COVERAGE" ]; then composer require --no-interaction --no-update phpunit/phpcov; fi
+          if [ -n "$LOG_COVERAGE" ]; then composer require --no-interaction --no-install phpunit/phpcov; fi
           composer update --ansi --prefer-dist --no-interaction --no-progress --optimize-autoloader
           if [ "${{ matrix.type }}" = "Chrome Lowest" ]; then composer update --ansi --prefer-dist --prefer-lowest --prefer-stable --no-interaction --no-progress --optimize-autoloader; fi
 
diff --git a/composer.json b/composer.json
index df62ee2afe..8e2f8db800 100644
--- a/composer.json
+++ b/composer.json
@@ -51,7 +51,7 @@
     ],
     "homepage": "https://github.com/atk4/ui",
     "require": {
-        "php": ">=7.4 <8.3",
+        "php": ">=7.4 <8.4",
         "atk4/data": "dev-develop",
         "nyholm/psr7": "^1.4",
         "nyholm/psr7-server": "^1.0",
@@ -59,7 +59,7 @@
         "symfony/http-foundation": "^4.4 || ^5.3 || ^6.0"
     },
     "require-release": {
-        "php": ">=7.4 <8.3",
+        "php": ">=7.4 <8.4",
         "atk4/data": "~5.0.0",
         "nyholm/psr7": "^1.4",
         "nyholm/psr7-server": "^1.0",
diff --git a/src/App.php b/src/App.php
index d827d7fd29..880a03349d 100644
--- a/src/App.php
+++ b/src/App.php
@@ -204,7 +204,9 @@ public function __construct(array $defaults = [])
 
                 throw new \ErrorException($msg, 0, $severity, $file, $line);
             });
-            http_response_code(500);
+            if (\PHP_SAPI !== 'cli') { // for phpunit
+                http_response_code(500);
+            }
         }
 
         // always run app on shutdown
@@ -1078,7 +1080,9 @@ function () {
      */
     protected function emitResponse(): void
     {
-        http_response_code($this->response->getStatusCode());
+        if (!headers_sent() || $this->response->getHeaders() !== []) { // avoid throwing late error in loop
+            http_response_code($this->response->getStatusCode());
+        }
 
         foreach ($this->response->getHeaders() as $name => $values) {
             foreach ($values as $value) {
diff --git a/src/App/SessionManager.php b/src/App/SessionManager.php
index ee2834f27a..dac382f88c 100644
--- a/src/App/SessionManager.php
+++ b/src/App/SessionManager.php
@@ -57,9 +57,11 @@ protected function closeSession(bool $writeBeforeClose): void
     }
 
     /**
-     * @param \Closure(): mixed $fx
+     * @template T
      *
-     * @return mixed
+     * @param \Closure(): T $fx
+     *
+     * @return T
      */
     public function atomicSession(\Closure $fx, bool $readAndCloseImmediately = false)
     {
diff --git a/src/Callback.php b/src/Callback.php
index 4ea428cc49..a29460d522 100644
--- a/src/Callback.php
+++ b/src/Callback.php
@@ -67,7 +67,7 @@ public function getUrlTrigger(): string
      * @param \Closure(mixed, mixed, mixed, mixed, mixed, mixed, mixed, mixed, mixed, mixed): T $fx
      * @param array                                                                             $fxArgs
      *
-     * @phpstan-return T|null
+     * @return T|null
      */
     public function set($fx = null, $fxArgs = null)
     {
diff --git a/src/Console.php b/src/Console.php
index 290b84bf01..f76e29c2ee 100644
--- a/src/Console.php
+++ b/src/Console.php
@@ -446,10 +446,8 @@ public function debug($message, array $context = []): void
 
     /**
      * @param 'emergency'|'alert'|'critical'|'error'|'warning'|'notice'|'info'|'debug' $level
-     *
-     * @phpstan-ignore-next-line
      */
-    public function log($level, $message, array $context = []): void
+    public function log($level, $message, array $context = []): void // @phpstan-ignore-line
     {
         $this->{$level}($message, $context);
     }
diff --git a/src/Form/Control.php b/src/Form/Control.php
index 9d8f6665cc..467d481dbd 100644
--- a/src/Form/Control.php
+++ b/src/Form/Control.php
@@ -24,11 +24,7 @@ class Control extends View
     /** @var Form|null to which this field belongs */
     public $form;
 
-    /**
-     * @var EntityFieldPair|null
-     *
-     * @phpstan-var EntityFieldPair<Model, Field>|null
-     */
+    /** @var EntityFieldPair<Model, Field>|null */
     public $entityField;
 
     /** @var string */
diff --git a/src/Form/Control/ScopeBuilder.php b/src/Form/Control/ScopeBuilder.php
index 508b99fdcf..9031e6a256 100644
--- a/src/Form/Control/ScopeBuilder.php
+++ b/src/Form/Control/ScopeBuilder.php
@@ -692,7 +692,7 @@ protected function getConditionOption(string $type, $value, Condition $condition
     /**
      * Auto-detects a string delimiter based on list of predefined values in ScopeBuilder::$listDelimiters in order of priority.
      *
-     * @phpstan-return non-empty-string
+     * @return non-empty-string
      */
     public function detectDelimiter(string $value): string
     {
diff --git a/src/SessionTrait.php b/src/SessionTrait.php
index 6015116cfc..aa15719cdb 100644
--- a/src/SessionTrait.php
+++ b/src/SessionTrait.php
@@ -19,9 +19,11 @@ private function getSessionManager(): App\SessionManager
     }
 
     /**
-     * @param \Closure(): mixed $fx
+     * @template T
      *
-     * @return mixed
+     * @param \Closure(): T $fx
+     *
+     * @return T
      */
     public function atomicSession(\Closure $fx, bool $readAndCloseImmediately = false)
     {
diff --git a/src/UserAction/JsCallbackExecutor.php b/src/UserAction/JsCallbackExecutor.php
index 8dd1493ccf..4388e15fc6 100644
--- a/src/UserAction/JsCallbackExecutor.php
+++ b/src/UserAction/JsCallbackExecutor.php
@@ -53,10 +53,12 @@ public function setAction(Model\UserAction $action)
     }
 
     /**
-     * @param \Closure(): mixed     $fx
+     * @template T
+     *
+     * @param \Closure(): T         $fx
      * @param array<string, string> $urlArgs
      *
-     * @return mixed
+     * @return T
      */
     protected function invokeFxWithUrlArgs(\Closure $fx, array $urlArgs = [])
     {
diff --git a/src/View.php b/src/View.php
index c27d78d888..b7503a13e6 100644
--- a/src/View.php
+++ b/src/View.php
@@ -312,7 +312,7 @@ public function add($object, $region = null): AbstractView
      *
      * @param class-string<T> $class
      *
-     * @phpstan-return T|null
+     * @return T|null
      */
     public function getClosestOwner(string $class): ?self
     {