diff --git a/src/Psalm/Internal/Cli/LanguageServer.php b/src/Psalm/Internal/Cli/LanguageServer.php
index 1dc16fbe5..0fa174eff 100644
--- a/src/Psalm/Internal/Cli/LanguageServer.php
+++ b/src/Psalm/Internal/Cli/LanguageServer.php
@@ -258,12 +258,12 @@ final class LanguageServer
             $options['r'] = $options['root'];
         }
 
-        $current_dir = (string)getcwd() . DIRECTORY_SEPARATOR;
+        $current_dir = (string) getcwd();
 
         if (isset($options['r']) && is_string($options['r'])) {
             $root_path = realpath($options['r']);
 
-            if (!$root_path) {
+            if ($root_path === false) {
                 fwrite(
                     STDERR,
                     'Could not locate root directory ' . $current_dir . DIRECTORY_SEPARATOR . $options['r'] . PHP_EOL,
@@ -271,7 +271,7 @@ final class LanguageServer
                 exit(1);
             }
 
-            $current_dir = $root_path . DIRECTORY_SEPARATOR;
+            $current_dir = $root_path;
         }
 
         $vendor_dir = CliUtils::getVendorDir($current_dir);
diff --git a/src/Psalm/Internal/Cli/Plugin.php b/src/Psalm/Internal/Cli/Plugin.php
index 238823826..c89cbeed5 100644
--- a/src/Psalm/Internal/Cli/Plugin.php
+++ b/src/Psalm/Internal/Cli/Plugin.php
@@ -12,8 +12,6 @@ use Symfony\Component\Console\Application;
 use function dirname;
 use function getcwd;
 
-use const DIRECTORY_SEPARATOR;
-
 // phpcs:disable PSR1.Files.SideEffects
 
 require_once __DIR__ . '/../CliUtils.php';
@@ -27,13 +25,13 @@ final class Plugin
     public static function run(): void
     {
         CliUtils::checkRuntimeRequirements();
-        $current_dir = (string)getcwd() . DIRECTORY_SEPARATOR;
+        $current_dir = (string) getcwd();
         $vendor_dir = CliUtils::getVendorDir($current_dir);
         CliUtils::requireAutoloaders($current_dir, false, $vendor_dir);
 
         $app = new Application('psalm-plugin', PSALM_VERSION);
 
-        $psalm_root = dirname(__DIR__, 4) . DIRECTORY_SEPARATOR;
+        $psalm_root = dirname(__DIR__, 4);
 
         $plugin_list_factory = new PluginListFactory($current_dir, $psalm_root);
 
diff --git a/src/Psalm/Internal/Cli/Psalm.php b/src/Psalm/Internal/Cli/Psalm.php
index c354cf21a..c8a5a4ee2 100644
--- a/src/Psalm/Internal/Cli/Psalm.php
+++ b/src/Psalm/Internal/Cli/Psalm.php
@@ -485,7 +485,7 @@ final class Psalm
      */
     private static function generateConfig(string $current_dir, array &$args): void
     {
-        if (file_exists($current_dir . 'psalm.xml')) {
+        if (file_exists($current_dir . DIRECTORY_SEPARATOR . 'psalm.xml')) {
             die('A config file already exists in the current directory' . PHP_EOL);
         }
 
@@ -535,7 +535,7 @@ final class Psalm
                 die($e->getMessage() . PHP_EOL);
             }
 
-            if (!file_put_contents($current_dir . 'psalm.xml', $template_contents)) {
+            if (!file_put_contents($current_dir . DIRECTORY_SEPARATOR . 'psalm.xml', $template_contents)) {
                 die('Could not write to psalm.xml' . PHP_EOL);
             }
 
@@ -779,7 +779,7 @@ final class Psalm
             die($e->getMessage() . PHP_EOL);
         }
 
-        if (!file_put_contents($current_dir . 'psalm.xml', $template_contents)) {
+        if (!file_put_contents($current_dir . DIRECTORY_SEPARATOR . 'psalm.xml', $template_contents)) {
             die('Could not write to psalm.xml' . PHP_EOL);
         }
 
@@ -840,12 +840,12 @@ final class Psalm
             exit(1);
         }
 
-        $current_dir = $cwd . DIRECTORY_SEPARATOR;
+        $current_dir = $cwd;
 
         if (isset($options['r']) && is_string($options['r'])) {
             $root_path = realpath($options['r']);
 
-            if (!$root_path) {
+            if ($root_path === false) {
                 fwrite(
                     STDERR,
                     'Could not locate root directory ' . $current_dir . DIRECTORY_SEPARATOR . $options['r'] . PHP_EOL,
@@ -853,7 +853,7 @@ final class Psalm
                 exit(1);
             }
 
-            $current_dir = $root_path . DIRECTORY_SEPARATOR;
+            $current_dir = $root_path;
         }
 
         return $current_dir;
diff --git a/src/Psalm/Internal/Cli/Psalter.php b/src/Psalm/Internal/Cli/Psalter.php
index 9dd8eaf47..5b53ec0dc 100644
--- a/src/Psalm/Internal/Cli/Psalter.php
+++ b/src/Psalm/Internal/Cli/Psalter.php
@@ -194,16 +194,16 @@ final class Psalter
             exit(1);
         }
 
-        $current_dir = (string)getcwd() . DIRECTORY_SEPARATOR;
+        $current_dir = (string) getcwd();
 
         if (isset($options['r']) && is_string($options['r'])) {
             $root_path = realpath($options['r']);
 
-            if (!$root_path) {
+            if ($root_path === false) {
                 die('Could not locate root directory ' . $current_dir . DIRECTORY_SEPARATOR . $options['r'] . PHP_EOL);
             }
 
-            $current_dir = $root_path . DIRECTORY_SEPARATOR;
+            $current_dir = $root_path;
         }
 
         $vendor_dir = CliUtils::getVendorDir($current_dir);
diff --git a/src/Psalm/Internal/Cli/Refactor.php b/src/Psalm/Internal/Cli/Refactor.php
index 0fca3ab46..22761b873 100644
--- a/src/Psalm/Internal/Cli/Refactor.php
+++ b/src/Psalm/Internal/Cli/Refactor.php
@@ -165,16 +165,16 @@ final class Refactor
             $options['r'] = $options['root'];
         }
 
-        $current_dir = (string)getcwd() . DIRECTORY_SEPARATOR;
+        $current_dir = (string) getcwd();
 
         if (isset($options['r']) && is_string($options['r'])) {
             $root_path = realpath($options['r']);
 
-            if (!$root_path) {
+            if ($root_path === false) {
                 die('Could not locate root directory ' . $current_dir . DIRECTORY_SEPARATOR . $options['r'] . PHP_EOL);
             }
 
-            $current_dir = $root_path . DIRECTORY_SEPARATOR;
+            $current_dir = $root_path;
         }
 
         $vendor_dir = CliUtils::getVendorDir($current_dir);
diff --git a/src/Psalm/Internal/PluginManager/Command/DisableCommand.php b/src/Psalm/Internal/PluginManager/Command/DisableCommand.php
index af7b4bb90..7c1e6b9a2 100644
--- a/src/Psalm/Internal/PluginManager/Command/DisableCommand.php
+++ b/src/Psalm/Internal/PluginManager/Command/DisableCommand.php
@@ -16,8 +16,6 @@ use function assert;
 use function getcwd;
 use function is_string;
 
-use const DIRECTORY_SEPARATOR;
-
 /**
  * @internal
  */
@@ -50,7 +48,7 @@ final class DisableCommand extends Command
     {
         $io = new SymfonyStyle($input, $output);
 
-        $current_dir = (string) getcwd() . DIRECTORY_SEPARATOR;
+        $current_dir = (string) getcwd();
 
         $config_file_path = $input->getOption('config');
         if ($config_file_path !== null && !is_string($config_file_path)) {
diff --git a/src/Psalm/Internal/PluginManager/Command/EnableCommand.php b/src/Psalm/Internal/PluginManager/Command/EnableCommand.php
index 6278b7018..0a8df8d1d 100644
--- a/src/Psalm/Internal/PluginManager/Command/EnableCommand.php
+++ b/src/Psalm/Internal/PluginManager/Command/EnableCommand.php
@@ -16,8 +16,6 @@ use function assert;
 use function getcwd;
 use function is_string;
 
-use const DIRECTORY_SEPARATOR;
-
 /**
  * @internal
  */
@@ -50,7 +48,7 @@ final class EnableCommand extends Command
     {
         $io = new SymfonyStyle($input, $output);
 
-        $current_dir = (string) getcwd() . DIRECTORY_SEPARATOR;
+        $current_dir = (string) getcwd();
 
         $config_file_path = $input->getOption('config');
         if ($config_file_path !== null && !is_string($config_file_path)) {
diff --git a/src/Psalm/Internal/PluginManager/Command/ShowCommand.php b/src/Psalm/Internal/PluginManager/Command/ShowCommand.php
index a8e78a732..ecc24712c 100644
--- a/src/Psalm/Internal/PluginManager/Command/ShowCommand.php
+++ b/src/Psalm/Internal/PluginManager/Command/ShowCommand.php
@@ -17,8 +17,6 @@ use function count;
 use function getcwd;
 use function is_string;
 
-use const DIRECTORY_SEPARATOR;
-
 /**
  * @internal
  */
@@ -44,7 +42,7 @@ final class ShowCommand extends Command
     protected function execute(InputInterface $input, OutputInterface $output): int
     {
         $io = new SymfonyStyle($input, $output);
-        $current_dir = (string) getcwd() . DIRECTORY_SEPARATOR;
+        $current_dir = (string) getcwd();
 
         $config_file_path = $input->getOption('config');
         if ($config_file_path !== null && !is_string($config_file_path)) {
diff --git a/src/Psalm/Internal/PluginManager/PluginListFactory.php b/src/Psalm/Internal/PluginManager/PluginListFactory.php
index 950b6dd24..927d0f8c3 100644
--- a/src/Psalm/Internal/PluginManager/PluginListFactory.php
+++ b/src/Psalm/Internal/PluginManager/PluginListFactory.php
@@ -7,10 +7,8 @@ use RuntimeException;
 
 use function array_filter;
 use function json_encode;
-use function rtrim;
 use function urlencode;
 
-use const DIRECTORY_SEPARATOR;
 use const JSON_THROW_ON_ERROR;
 
 /**
@@ -53,13 +51,13 @@ final class PluginListFactory
         if ($this->psalm_root === $this->project_root) {
             // managing plugins for psalm itself
             $composer_lock_filenames = [
-                Composer::getLockFilePath(rtrim($this->psalm_root, DIRECTORY_SEPARATOR)),
+                Composer::getLockFilePath($this->psalm_root),
             ];
         } else {
             $composer_lock_filenames = [
-                Composer::getLockFilePath(rtrim($this->project_root, DIRECTORY_SEPARATOR)),
-                Composer::getLockFilePath(rtrim($this->psalm_root, DIRECTORY_SEPARATOR) . '/../../..'),
-                Composer::getLockFilePath(rtrim($this->psalm_root, DIRECTORY_SEPARATOR)),
+                Composer::getLockFilePath($this->project_root),
+                Composer::getLockFilePath($this->psalm_root . '/../../..'),
+                Composer::getLockFilePath($this->psalm_root),
             ];
         }