diff --git a/src/Parser/CachedParser.php b/src/Parser/CachedParser.php
index 9a789330b1..f78bfc60f1 100644
--- a/src/Parser/CachedParser.php
+++ b/src/Parser/CachedParser.php
@@ -16,6 +16,9 @@ class CachedParser implements Parser
 
 	private int $cachedNodesByStringCountMax;
 
+	/** @var array<string, true> */
+	private array $parsedByString = [];
+
 	public function __construct(
 		Parser $originalParser,
 		int $cachedNodesByStringCountMax
@@ -43,9 +46,10 @@ public function parseFile(string $file): array
 		}
 
 		$sourceCode = FileReader::read($file);
-		if (!isset($this->cachedNodesByString[$sourceCode])) {
+		if (!isset($this->cachedNodesByString[$sourceCode]) || isset($this->parsedByString[$sourceCode])) {
 			$this->cachedNodesByString[$sourceCode] = $this->originalParser->parseFile($file);
 			$this->cachedNodesByStringCount++;
+			unset($this->parsedByString[$sourceCode]);
 		}
 
 		return $this->cachedNodesByString[$sourceCode];
@@ -71,6 +75,7 @@ public function parseString(string $sourceCode): array
 		if (!isset($this->cachedNodesByString[$sourceCode])) {
 			$this->cachedNodesByString[$sourceCode] = $this->originalParser->parseString($sourceCode);
 			$this->cachedNodesByStringCount++;
+			$this->parsedByString[$sourceCode] = true;
 		}
 
 		return $this->cachedNodesByString[$sourceCode];
diff --git a/tests/PHPStan/Parser/CachedParserTest.php b/tests/PHPStan/Parser/CachedParserTest.php
index b014507974..a76dd3f97c 100644
--- a/tests/PHPStan/Parser/CachedParserTest.php
+++ b/tests/PHPStan/Parser/CachedParserTest.php
@@ -2,7 +2,11 @@
 
 namespace PHPStan\Parser;
 
-class CachedParserTest extends \PHPUnit\Framework\TestCase
+use PhpParser\Node\Stmt\Namespace_;
+use PHPStan\File\FileReader;
+use PHPStan\Testing\TestCase;
+
+class CachedParserTest extends TestCase
 {
 
 	/**
@@ -75,4 +79,22 @@ private function getPhpParserNodeMock(): \PhpParser\Node
 		return $this->createMock(\PhpParser\Node::class);
 	}
 
+	public function testParseTheSameFileWithDifferentMethod(): void
+	{
+		$parser = new CachedParser(self::getContainer()->getService('pathRoutingParser'), 500);
+		$path = __DIR__ . '/data/test.php';
+		$contents = FileReader::read($path);
+		$stmts = $parser->parseString($contents);
+		$this->assertInstanceOf(Namespace_::class, $stmts[0]);
+		$this->assertNull($stmts[0]->stmts[0]->getAttribute('parent'));
+
+		$stmts = $parser->parseFile($path);
+		$this->assertInstanceOf(Namespace_::class, $stmts[0]);
+		$this->assertInstanceOf(Namespace_::class, $stmts[0]->stmts[0]->getAttribute('parent'));
+
+		$stmts = $parser->parseString($contents);
+		$this->assertInstanceOf(Namespace_::class, $stmts[0]);
+		$this->assertInstanceOf(Namespace_::class, $stmts[0]->stmts[0]->getAttribute('parent'));
+	}
+
 }
diff --git a/tests/PHPStan/Parser/data/test.php b/tests/PHPStan/Parser/data/test.php
new file mode 100644
index 0000000000..a6bee51214
--- /dev/null
+++ b/tests/PHPStan/Parser/data/test.php
@@ -0,0 +1,8 @@
+<?php
+
+namespace CachedParserBug;
+
+class Foo
+{
+
+}