diff --git a/Makefile b/Makefile
index 0dd639c3..ba7b8ffe 100644
--- a/Makefile
+++ b/Makefile
@@ -35,7 +35,7 @@ unit-tests:
 	./vendor/bin/phpunit -c config/phpunit.xml.dist
 
 mutation-tests:                                                                     ## run mutation tests
-	./vendor/bin/roave-infection-static-analysis-plugin run --configuration=config/infection.json.dist --psalm-config=config/psalm.xml
+	./vendor/bin/roave-infection-static-analysis-plugin --configuration=config/infection.json.dist --psalm-config=config/psalm.xml
 
 code-coverage: unit-tests                                                       ## generate and upload test coverage metrics to https://coveralls.io/
 	./vendor/bin/php-coveralls -x var/clover.xml -o var/coveralls-upload.json -v
diff --git a/composer.lock b/composer.lock
index bf418ed4..003dccfe 100644
--- a/composer.lock
+++ b/composer.lock
@@ -6504,16 +6504,16 @@
         },
         {
             "name": "vimeo/psalm",
-            "version": "5.15.0",
+            "version": "5.17.0",
             "source": {
                 "type": "git",
                 "url": "https://github.com/vimeo/psalm.git",
-                "reference": "5c774aca4746caf3d239d9c8cadb9f882ca29352"
+                "reference": "c620f6e80d0abfca532b00bda366062aaedf6e5d"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/vimeo/psalm/zipball/5c774aca4746caf3d239d9c8cadb9f882ca29352",
-                "reference": "5c774aca4746caf3d239d9c8cadb9f882ca29352",
+                "url": "https://api.github.com/repos/vimeo/psalm/zipball/c620f6e80d0abfca532b00bda366062aaedf6e5d",
+                "reference": "c620f6e80d0abfca532b00bda366062aaedf6e5d",
                 "shasum": ""
             },
             "require": {
@@ -6538,8 +6538,8 @@
                 "php": "^7.4 || ~8.0.0 || ~8.1.0 || ~8.2.0 || ~8.3.0",
                 "sebastian/diff": "^4.0 || ^5.0",
                 "spatie/array-to-xml": "^2.17.0 || ^3.0",
-                "symfony/console": "^4.1.6 || ^5.0 || ^6.0",
-                "symfony/filesystem": "^5.4 || ^6.0"
+                "symfony/console": "^4.1.6 || ^5.0 || ^6.0 || ^7.0",
+                "symfony/filesystem": "^5.4 || ^6.0 || ^7.0"
             },
             "conflict": {
                 "nikic/php-parser": "4.17.0"
@@ -6561,7 +6561,7 @@
                 "psalm/plugin-phpunit": "^0.18",
                 "slevomat/coding-standard": "^8.4",
                 "squizlabs/php_codesniffer": "^3.6",
-                "symfony/process": "^4.4 || ^5.0 || ^6.0"
+                "symfony/process": "^4.4 || ^5.0 || ^6.0 || ^7.0"
             },
             "suggest": {
                 "ext-curl": "In order to send data to shepherd",
@@ -6574,7 +6574,7 @@
                 "psalm-refactor",
                 "psalter"
             ],
-            "type": "library",
+            "type": "project",
             "extra": {
                 "branch-alias": {
                     "dev-master": "5.x-dev",
@@ -6606,10 +6606,11 @@
                 "static analysis"
             ],
             "support": {
+                "docs": "https://psalm.dev/docs",
                 "issues": "https://github.com/vimeo/psalm/issues",
-                "source": "https://github.com/vimeo/psalm/tree/5.15.0"
+                "source": "https://github.com/vimeo/psalm"
             },
-            "time": "2023-08-20T23:07:30+00:00"
+            "time": "2023-12-03T20:21:41+00:00"
         },
         {
             "name": "webmozart/assert",
diff --git a/src/Psl/Internal/box.php b/src/Psl/Internal/box.php
index 87065e50..0f8098e6 100644
--- a/src/Psl/Internal/box.php
+++ b/src/Psl/Internal/box.php
@@ -29,9 +29,6 @@ function box(Closure $fun): array
         $last_message = $message;
     });
 
-    /**
-     * @var string|null $last_message
-     */
     if (null !== $last_message && Str\contains($last_message, '): ')) {
         $last_message = Str\after(
             Str\lowercase($last_message),
diff --git a/src/Psl/Network/Internal/socket_connect.php b/src/Psl/Network/Internal/socket_connect.php
index 9d4f4bb9..50420a27 100644
--- a/src/Psl/Network/Internal/socket_connect.php
+++ b/src/Psl/Network/Internal/socket_connect.php
@@ -9,6 +9,7 @@
 use Revolt\EventLoop;
 
 use function fclose;
+use function is_resource;
 use function stream_context_create;
 use function stream_socket_client;
 
@@ -42,10 +43,12 @@ function socket_connect(string $uri, array $context = [], ?float $timeout = null
         $timeout_watcher = '';
         if (null !== $timeout) {
             $timeout_watcher = EventLoop::delay($timeout, static function () use ($suspension, &$write_watcher, $socket) {
-                /** @var string $write_watcher */
                 EventLoop::cancel($write_watcher);
 
-                fclose($socket);
+                /** @psalm-suppress RedundantCondition - it can be resource|closed-resource */
+                if (is_resource($socket)) {
+                    fclose($socket);
+                }
 
                 $suspension->throw(new Exception\TimeoutException('Connection to socket timed out.'));
             });
diff --git a/src/Psl/Shell/execute.php b/src/Psl/Shell/execute.php
index 89df1d77..03519e9d 100644
--- a/src/Psl/Shell/execute.php
+++ b/src/Psl/Shell/execute.php
@@ -86,7 +86,6 @@ static function (array $m) use (
                     return $m[0];
                 }
 
-                /** @var array<string, string> $variable_cache */
                 if (isset($variable_cache[$m[0]])) {
                     /** @var string */
                     return $variable_cache[$m[0]];
@@ -101,15 +100,8 @@ static function (array $m) use (
                     return '"' . $value . '"';
                 }
 
-                /**
-                 * @var string $var
-                 * @var int $variable_count
-                 */
                 $var = $identifier . ((string) ++$variable_count);
 
-                /**
-                 * @var array<string, string> $environment
-                 */
                 $environment[$var] = '"' . Regex\replace(
                     Str\Byte\replace_every(
                         $value,
@@ -137,7 +129,6 @@ static function (array $m) use (
         1 => ['pipe', 'w'],
         2 => ['pipe', 'w'],
     ];
-    /** @var array<string, string> $environment */
     $process = proc_open($commandline, $descriptor, $pipes, $working_directory, $environment, $options);
     // @codeCoverageIgnoreStart
     // not sure how to replicate this, but it can happen \_o.o_/