diff --git a/composer.json b/composer.json
index 776c84b96..a45f0f60f 100644
--- a/composer.json
+++ b/composer.json
@@ -50,7 +50,7 @@
         "rector/rector": "^0.15.18",
         "roave/infection-static-analysis-plugin": "^1.16",
         "spatie/phpunit-watcher": "^1.23",
-        "vimeo/psalm": "^4.30|^5.7",
+        "vimeo/psalm": "^5.18",
         "yiisoft/error-handler": "^3.0",
         "yiisoft/event-dispatcher": "^1.0",
         "yiisoft/log": "^2.0",
diff --git a/psalm.xml b/psalm.xml
index 471615b1a..2219c8dac 100644
--- a/psalm.xml
+++ b/psalm.xml
@@ -1,6 +1,6 @@
 <?xml version="1.0"?>
 <psalm
-    errorLevel="5"
+    errorLevel="4"
     findUnusedBaselineEntry="true"
     findUnusedCode="false"
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
@@ -13,4 +13,7 @@
             <directory name="vendor" />
         </ignoreFiles>
     </projectFiles>
+    <issueHandlers>
+        <MixedAssignment errorLevel="suppress" />
+    </issueHandlers>
 </psalm>
diff --git a/src/Collector/Console/CommandCollector.php b/src/Collector/Console/CommandCollector.php
index b97e64f1f..0f14a83b4 100644
--- a/src/Collector/Console/CommandCollector.php
+++ b/src/Collector/Console/CommandCollector.php
@@ -68,17 +68,14 @@ public function collect(ConsoleEvent|ConsoleErrorEvent|ConsoleTerminateEvent $ev
             return;
         }
 
-        /** @noinspection PhpConditionAlreadyCheckedInspection */
-        if ($event instanceof ConsoleEvent) {
-            $this->commands[$event::class] = [
-                'name' => $command->getName(),
-                'command' => $command,
-                'input' => $this->castInputToString($event->getInput()),
-                'output' => $this->fetchOutput($event->getOutput()),
-                'arguments' => $command->getDefinition()->getArguments(),
-                'options' => $command->getDefinition()->getOptions(),
-            ];
-        }
+        $this->commands[$event::class] = [
+            'name' => $command->getName(),
+            'command' => $command,
+            'input' => $this->castInputToString($event->getInput()),
+            'output' => $this->fetchOutput($event->getOutput()),
+            'arguments' => $command->getDefinition()->getArguments(),
+            'options' => $command->getDefinition()->getOptions(),
+        ];
     }
 
     public function getSummary(): array
diff --git a/src/Collector/Stream/FilesystemStreamProxy.php b/src/Collector/Stream/FilesystemStreamProxy.php
index d0ab06133..75fdd865e 100644
--- a/src/Collector/Stream/FilesystemStreamProxy.php
+++ b/src/Collector/Stream/FilesystemStreamProxy.php
@@ -11,14 +11,14 @@
 
 use const SEEK_SET;
 
-class FilesystemStreamProxy implements StreamWrapperInterface
+final class FilesystemStreamProxy implements StreamWrapperInterface
 {
     public static bool $registered = false;
     /**
      * @var resource|null
      */
     public $context;
-    public StreamWrapperInterface $decorated;
+    public StreamWrapper $decorated;
     public bool $ignored = false;
 
     public static ?FilesystemStreamCollector $collector = null;
diff --git a/src/Collector/Stream/HttpStreamProxy.php b/src/Collector/Stream/HttpStreamProxy.php
index f4c7e7ff4..cd85ffac1 100644
--- a/src/Collector/Stream/HttpStreamProxy.php
+++ b/src/Collector/Stream/HttpStreamProxy.php
@@ -13,7 +13,7 @@
 
 use const SEEK_SET;
 
-class HttpStreamProxy implements StreamWrapperInterface
+final class HttpStreamProxy implements StreamWrapperInterface
 {
     public static bool $registered = false;
     public static array $ignoredPathPatterns = [];
@@ -23,7 +23,7 @@ class HttpStreamProxy implements StreamWrapperInterface
      * @var resource|null
      */
     public $context;
-    public StreamWrapperInterface $decorated;
+    public StreamWrapper $decorated;
     public bool $ignored = false;
 
     public static ?HttpStreamCollector $collector = null;
diff --git a/src/Collector/Web/RequestCollector.php b/src/Collector/Web/RequestCollector.php
index 3dcb9ab48..c9b91a367 100644
--- a/src/Collector/Web/RequestCollector.php
+++ b/src/Collector/Web/RequestCollector.php
@@ -13,8 +13,6 @@
 use Yiisoft\Yii\Http\Event\AfterRequest;
 use Yiisoft\Yii\Http\Event\BeforeRequest;
 
-use function is_object;
-
 final class RequestCollector implements SummaryCollectorInterface
 {
     use CollectorTrait;
@@ -68,7 +66,7 @@ public function getCollected(): array
 
     public function collect(object $event): void
     {
-        if (!is_object($event) || !$this->isActive()) {
+        if (!$this->isActive()) {
             return;
         }
 
diff --git a/src/Helper/StreamWrapper/StreamWrapper.php b/src/Helper/StreamWrapper/StreamWrapper.php
index cda2ee633..859c9b4a5 100644
--- a/src/Helper/StreamWrapper/StreamWrapper.php
+++ b/src/Helper/StreamWrapper/StreamWrapper.php
@@ -32,6 +32,10 @@ final class StreamWrapper implements StreamWrapperInterface
     public function dir_closedir(): bool
     {
         closedir($this->stream);
+
+        /**
+         * @psalm-suppress RedundantCondition
+         */
         return is_resource($this->stream);
     }
 
@@ -54,7 +58,11 @@ public function dir_rewinddir(): bool
         }
 
         rewinddir($this->stream);
-        /** @noinspection PhpConditionAlreadyCheckedInspection */
+
+        /**
+         * @noinspection PhpConditionAlreadyCheckedInspection
+         * @psalm-suppress RedundantCondition
+         */
         return is_resource($this->stream);
     }