diff --git a/src/Rules/Deprecations/TypeHintDeprecatedInClosureSignatureRule.php b/src/Rules/Deprecations/TypeHintDeprecatedInClosureSignatureRule.php
index 193bd37..bfb83a1 100644
--- a/src/Rules/Deprecations/TypeHintDeprecatedInClosureSignatureRule.php
+++ b/src/Rules/Deprecations/TypeHintDeprecatedInClosureSignatureRule.php
@@ -5,7 +5,6 @@
 use PhpParser\Node;
 use PHPStan\Analyser\Scope;
 use PHPStan\Node\InClosureNode;
-use PHPStan\Reflection\ParametersAcceptor;
 use PHPStan\Rules\Rule;
 use PHPStan\ShouldNotHappenException;
 use function sprintf;
@@ -36,7 +35,7 @@ public function processNode(Node $node, Scope $scope): array
 		}
 
 		$functionSignature = $scope->getAnonymousFunctionReflection();
-		if (!$functionSignature instanceof ParametersAcceptor) {
+		if ($functionSignature === null) {
 			throw new ShouldNotHappenException();
 		}
 
diff --git a/src/Rules/Deprecations/TypeHintDeprecatedInFunctionSignatureRule.php b/src/Rules/Deprecations/TypeHintDeprecatedInFunctionSignatureRule.php
index 961282b..9c91ec9 100644
--- a/src/Rules/Deprecations/TypeHintDeprecatedInFunctionSignatureRule.php
+++ b/src/Rules/Deprecations/TypeHintDeprecatedInFunctionSignatureRule.php
@@ -5,7 +5,6 @@
 use PhpParser\Node;
 use PHPStan\Analyser\Scope;
 use PHPStan\Node\InFunctionNode;
-use PHPStan\Reflection\FunctionReflection;
 use PHPStan\Reflection\ParametersAcceptorSelector;
 use PHPStan\Rules\Rule;
 use PHPStan\ShouldNotHappenException;
@@ -37,7 +36,7 @@ public function processNode(Node $node, Scope $scope): array
 		}
 
 		$function = $scope->getFunction();
-		if (!$function instanceof FunctionReflection) {
+		if ($function === null) {
 			throw new ShouldNotHappenException();
 		}
 		$functionSignature = ParametersAcceptorSelector::selectSingle($function->getVariants());