diff --git a/src/Rules/PHPUnit/MockMethodCallRule.php b/src/Rules/PHPUnit/MockMethodCallRule.php
index cac776c..da8a95d 100644
--- a/src/Rules/PHPUnit/MockMethodCallRule.php
+++ b/src/Rules/PHPUnit/MockMethodCallRule.php
@@ -76,10 +76,15 @@ public function processNode(Node $node, Scope $scope): array
 				continue;
 			}
 
+			$classNames = $mockedClassObject->getObjectClassNames();
+			if (count($classNames) === 0) {
+				continue;
+			}
+
 			$errors[] = sprintf(
 				'Trying to mock an undefined method %s() on class %s.',
 				$method,
-				implode('|', $mockedClassObject->getObjectClassNames())
+				implode('|', $classNames)
 			);
 		}
 
diff --git a/tests/Rules/PHPUnit/data/mock-method-call.php b/tests/Rules/PHPUnit/data/mock-method-call.php
index 478fa44..a4f5aaa 100644
--- a/tests/Rules/PHPUnit/data/mock-method-call.php
+++ b/tests/Rules/PHPUnit/data/mock-method-call.php
@@ -56,3 +56,18 @@ public function method(string $string)
 		return $string;
 	}
 };
+
+final class FinalFoo
+{
+
+}
+
+class FinalFooTest extends \PHPUnit\Framework\TestCase
+{
+
+	public function testMockFinalClass()
+	{
+		$this->createMock(FinalFoo::class)->method('doFoo');
+	}
+
+}