diff --git a/src/Type/FileTypeMapper.php b/src/Type/FileTypeMapper.php
index c446b627a4..1baec0b9da 100644
--- a/src/Type/FileTypeMapper.php
+++ b/src/Type/FileTypeMapper.php
@@ -367,7 +367,7 @@ function (Node $node) use ($fileName, $lookForTrait, &$traitFound, $traitMethodA
 				}
 
 				if ($node instanceof Node\Stmt\Namespace_) {
-					$namespace = (string) $node->name;
+					$namespace = $node->name !== null ? (string) $node->name : null;
 				} elseif ($node instanceof Node\Stmt\Use_) {
 					if ($node->type === Node\Stmt\Use_::TYPE_NORMAL) {
 						foreach ($node->uses as $use) {
diff --git a/tests/PHPStan/Analyser/NodeScopeResolverTest.php b/tests/PHPStan/Analyser/NodeScopeResolverTest.php
index f0eb2fbf3f..c706e719f9 100644
--- a/tests/PHPStan/Analyser/NodeScopeResolverTest.php
+++ b/tests/PHPStan/Analyser/NodeScopeResolverTest.php
@@ -1042,6 +1042,7 @@ public function dataFileAsserts(): iterable
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-7963-three.php');
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-8017.php');
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-8004.php');
+		yield from $this->gatherAssertTypes(__DIR__ . '/data/global-namespace.php');
 	}
 
 	/**
diff --git a/tests/PHPStan/Analyser/data/global-namespace.php b/tests/PHPStan/Analyser/data/global-namespace.php
new file mode 100644
index 0000000000..971e0abd60
--- /dev/null
+++ b/tests/PHPStan/Analyser/data/global-namespace.php
@@ -0,0 +1,18 @@
+<?php
+
+namespace {
+
+	use function PHPStan\Testing\assertType;
+
+	/**
+	 * @return Exception
+	 */
+	function globalNamespaceTest()
+	{
+		return new Exception();
+	}
+
+	function () {
+		assertType('Exception', globalNamespaceTest());
+	};
+}