diff --git a/conf/config.level2.neon b/conf/config.level2.neon
index 31d4874741..b44a73faa7 100644
--- a/conf/config.level2.neon
+++ b/conf/config.level2.neon
@@ -28,6 +28,7 @@ rules:
 	- PHPStan\Rules\PhpDoc\IncompatiblePhpDocTypeRule
 	- PHPStan\Rules\PhpDoc\IncompatiblePropertyPhpDocTypeRule
 	- PHPStan\Rules\PhpDoc\InvalidPhpDocTagValueRule
+	- PHPStan\Rules\PhpDoc\InvalidPHPStanDocTagRule
 	- PHPStan\Rules\PhpDoc\InvalidThrowsPhpDocValueRule
 	- PHPStan\Rules\PhpDoc\WrongVariableNameInVarTagRule
 
diff --git a/src/Rules/PhpDoc/InvalidPHPStanDocTagRule.php b/src/Rules/PhpDoc/InvalidPHPStanDocTagRule.php
new file mode 100644
index 0000000000..b53b00cc37
--- /dev/null
+++ b/src/Rules/PhpDoc/InvalidPHPStanDocTagRule.php
@@ -0,0 +1,85 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Rules\PhpDoc;
+
+use PhpParser\Node;
+use PHPStan\Analyser\Scope;
+use PHPStan\PhpDocParser\Lexer\Lexer;
+use PHPStan\PhpDocParser\Parser\PhpDocParser;
+use PHPStan\PhpDocParser\Parser\TokenIterator;
+use PHPStan\Rules\RuleErrorBuilder;
+
+/**
+ * @implements \PHPStan\Rules\Rule<\PhpParser\Node>
+ */
+class InvalidPHPStanDocTagRule implements \PHPStan\Rules\Rule
+{
+
+	private const POSSIBLE_PHPSTAN_TAGS = [
+		'@phpstan-param',
+		'@phpstan-var',
+		'@phpstan-template',
+		'@phpstan-extends',
+		'@phpstan-implements',
+		'@phpstan-use',
+		'@phpstan-template',
+		'@phpstan-template-covariant',
+		'@phpstan-return',
+	];
+
+	/** @var Lexer */
+	private $phpDocLexer;
+
+	/** @var PhpDocParser */
+	private $phpDocParser;
+
+	public function __construct(Lexer $phpDocLexer, PhpDocParser $phpDocParser)
+	{
+		$this->phpDocLexer = $phpDocLexer;
+		$this->phpDocParser = $phpDocParser;
+	}
+
+	public function getNodeType(): string
+	{
+		return \PhpParser\Node::class;
+	}
+
+	public function processNode(Node $node, Scope $scope): array
+	{
+		if (
+			!$node instanceof Node\Stmt\ClassLike
+			&& !$node instanceof Node\FunctionLike
+			&& !$node instanceof Node\Stmt\Foreach_
+			&& !$node instanceof Node\Stmt\Property
+			&& !$node instanceof Node\Expr\Assign
+			&& !$node instanceof Node\Expr\AssignRef
+		) {
+			return [];
+		}
+
+		$docComment = $node->getDocComment();
+		if ($docComment === null) {
+			return [];
+		}
+		$phpDocString = $docComment->getText();
+		$tokens = new TokenIterator($this->phpDocLexer->tokenize($phpDocString));
+		$phpDocNode = $this->phpDocParser->parse($tokens);
+
+		$errors = [];
+		foreach ($phpDocNode->getTags() as $phpDocTag) {
+			if (strpos($phpDocTag->name, '@phpstan-') !== 0
+				|| in_array($phpDocTag->name, self::POSSIBLE_PHPSTAN_TAGS, true)
+			) {
+				continue;
+			}
+
+			$errors[] = RuleErrorBuilder::message(sprintf(
+				'Encountered unknown tag that had the phpstan prefix: %s',
+				$phpDocTag->name
+			))->build();
+		}
+
+		return $errors;
+	}
+
+}
diff --git a/tests/PHPStan/Rules/PhpDoc/InvalidPHPStanDocTagRuleTest.php b/tests/PHPStan/Rules/PhpDoc/InvalidPHPStanDocTagRuleTest.php
new file mode 100644
index 0000000000..57cdbb0903
--- /dev/null
+++ b/tests/PHPStan/Rules/PhpDoc/InvalidPHPStanDocTagRuleTest.php
@@ -0,0 +1,36 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Rules\PhpDoc;
+
+use PHPStan\PhpDocParser\Lexer\Lexer;
+use PHPStan\PhpDocParser\Parser\PhpDocParser;
+
+/**
+ * @extends \PHPStan\Testing\RuleTestCase<InvalidPHPStanDocTagRule>
+ */
+class InvalidPHPStanDocTagRuleTest extends \PHPStan\Testing\RuleTestCase
+{
+
+	protected function getRule(): \PHPStan\Rules\Rule
+	{
+		return new InvalidPHPStanDocTagRule(
+			self::getContainer()->getByType(Lexer::class),
+			self::getContainer()->getByType(PhpDocParser::class)
+		);
+	}
+
+	public function testRule(): void
+	{
+		$this->analyse([__DIR__ . '/data/invalid-phpstan-doc.php'], [
+			[
+				'Encountered unknown tag that had the phpstan prefix: @phpstan-extens',
+				7,
+			],
+			[
+				'Encountered unknown tag that had the phpstan prefix: @phpstan-pararm',
+				14,
+			],
+		]);
+	}
+
+}
diff --git a/tests/PHPStan/Rules/PhpDoc/data/invalid-phpstan-doc.php b/tests/PHPStan/Rules/PhpDoc/data/invalid-phpstan-doc.php
new file mode 100644
index 0000000000..4b1efb0805
--- /dev/null
+++ b/tests/PHPStan/Rules/PhpDoc/data/invalid-phpstan-doc.php
@@ -0,0 +1,15 @@
+<?php
+
+namespace InvalidPHPStanDoc;
+
+class Baz{}
+/** @phpstan-extens Baz */
+class Boo extends Baz
+{
+	/**
+	 * @phpstan-template T
+	 * @phpstan-pararm class-string<T> $a
+	 * @phpstan-return T
+	 */
+	function foo(string $a){}
+}