diff --git a/src/PhpStormReflectionStubs/PhpStormStubsLocator.php b/src/PhpStormReflectionStubs/PhpStormStubsLocator.php
index fffd9109..08b1be99 100644
--- a/src/PhpStormReflectionStubs/PhpStormStubsLocator.php
+++ b/src/PhpStormReflectionStubs/PhpStormStubsLocator.php
@@ -40,7 +40,7 @@ private static function changeDetector(): ChangeDetector
     public function locate(ConstantId|NamedFunctionId|NamedClassId $id): ?Resource
     {
         $relativePath = match (true) {
-            $id instanceof ConstantId => defined($id->name) ? null : PhpStormStubsMap::CONSTANTS[$id->name] ?? null,
+            $id instanceof ConstantId => \defined($id->name) ? null : PhpStormStubsMap::CONSTANTS[$id->name] ?? null,
             $id instanceof NamedFunctionId => PhpStormStubsMap::FUNCTIONS[$id->name] ?? null,
             $id instanceof NamedClassId => PhpStormStubsMap::CLASSES[$id->name] ?? null,
         };