Try

Author: VincentLanglet

src/Rules/DeadCode/UnusedPrivateMethodRule.php

@@ -66,6 +66,10 @@ public function processNode(Node $node, Scope $scope): array
 			}
 
 			$methodReflection = $classReflection->getNativeMethod($methodName);
+			if ($methodReflection->getDeclaringClass()->getName() !== $classReflection->getName()) {
+				continue;
+			}
+
 			foreach ($this->extensionProvider->getExtensions() as $extension) {
 				if ($extension->isAlwaysUsed($methodReflection)) {
 					continue 2;

src/Rules/DeadCode/UnusedPrivatePropertyRule.php

@@ -97,6 +97,9 @@ public function processNode(Node $node, Scope $scope): array
 				}
 
 				$propertyReflection = $classReflection->getNativeProperty($propertyName);
+				if ($propertyReflection->getDeclaringClass()->getName() !== $classReflection->getName()) {
+					continue;
+				}
 
 				foreach ($this->extensionProvider->getExtensions() as $extension) {
 					if ($alwaysRead && $alwaysWritten) {