diff --git a/src/SourceLocator/Type/PhpInternalSourceLocator.php b/src/SourceLocator/Type/PhpInternalSourceLocator.php
index 0fc6a41f5..ee6fd2ee4 100644
--- a/src/SourceLocator/Type/PhpInternalSourceLocator.php
+++ b/src/SourceLocator/Type/PhpInternalSourceLocator.php
@@ -51,7 +51,8 @@ private function getClassSource(Identifier $identifier): InternalLocatedSource|n
             $reflectionClass = new CoreReflectionClass($className);
 
             if (strtolower($reflectionClass->getName()) !== strtolower($className)) {
-                $aliasName  = $className;
+                $aliasName = $className;
+                /** @psalm-var class-string|trait-string $className */
                 $className  = $reflectionClass->getName();
                 $identifier = new Identifier($className, $identifier->getType());
             }
diff --git a/tools/composer.json b/tools/composer.json
index f9f016727..601aaf951 100644
--- a/tools/composer.json
+++ b/tools/composer.json
@@ -4,7 +4,7 @@
         "infection/infection": "^0.35.4",
         "phpstan/phpstan": "^2.2.13",
         "phpstan/phpstan-phpunit": "^2.0.18",
-        "vimeo/psalm": "^6.16.1",
+        "vimeo/psalm": "^6.17.0",
         "roave/backward-compatibility-check": "^8.21.0"
     },
     "config": {
diff --git a/tools/composer.lock b/tools/composer.lock
index 8ff5b10dd..dad669cd9 100644
--- a/tools/composer.lock
+++ b/tools/composer.lock
@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "b4e0e66eaeb3f37e478572288588fb32",
+    "content-hash": "13a25ef51ecddd6d77405d1821026c98",
     "packages": [
         {
             "name": "amphp/amp",
@@ -8095,16 +8095,16 @@
         },
         {
             "name": "vimeo/psalm",
-            "version": "6.16.1",
+            "version": "6.17.0",
             "source": {
                 "type": "git",
                 "url": "https://github.com/vimeo/psalm.git",
-                "reference": "f1f5de594dc76faf8784e02d3dc4716c91c6f6ac"
+                "reference": "056992a902704e2b691d33f9bfe4a063e43c79f2"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/vimeo/psalm/zipball/f1f5de594dc76faf8784e02d3dc4716c91c6f6ac",
-                "reference": "f1f5de594dc76faf8784e02d3dc4716c91c6f6ac",
+                "url": "https://api.github.com/repos/vimeo/psalm/zipball/056992a902704e2b691d33f9bfe4a063e43c79f2",
+                "reference": "056992a902704e2b691d33f9bfe4a063e43c79f2",
                 "shasum": ""
             },
             "require": {
@@ -8128,7 +8128,7 @@
                 "netresearch/jsonmapper": "^5.0",
                 "nikic/php-parser": "^5.0.0",
                 "php": "~8.1.31 || ~8.2.27 || ~8.3.16 || ~8.4.3 || ~8.5.0",
-                "sebastian/diff": "^4.0 || ^5.0 || ^6.0 || ^7.0 || ^8.0",
+                "sebastian/diff": "^4.0 || ^5.0 || ^6.0 || ^7.0 || ^8.0 || ^9.0",
                 "spatie/array-to-xml": "^2.17.0 || ^3.0",
                 "symfony/console": "^6.0 || ^7.0 || ^8.0",
                 "symfony/filesystem": "~6.3.12 || ~6.4.3 || ^7.0.3 || ^8.0",
@@ -8209,7 +8209,7 @@
                 "issues": "https://github.com/vimeo/psalm/issues",
                 "source": "https://github.com/vimeo/psalm"
             },
-            "time": "2026-03-19T10:56:09+00:00"
+            "time": "2026-09-10T11:14:46+00:00"
         },
         {
             "name": "webmozart/assert",