diff --git a/lib/LongitudeOne/Core/Enum/AxisEnum.php b/lib/LongitudeOne/Core/Enum/AxisEnum.php
index ead644a..3cbbf1d 100644
--- a/lib/LongitudeOne/Core/Enum/AxisEnum.php
+++ b/lib/LongitudeOne/Core/Enum/AxisEnum.php
@@ -11,15 +11,6 @@
 
 declare(strict_types=1);
 
-/**
- * This file is part of the LongitudeOne GeoParser project.
- *
- * PHP 8.3 | 8.4 | 8.5
- *
- * Copyright LongitudeOne - Alexandre Tranchant - Derek J. Lambert.
- * Copyright 2024-2026.
- */
-
 namespace LongitudeOne\Core\Enum;
 
 /**
diff --git a/lib/LongitudeOne/Core/Exception/ExceptionInterface.php b/lib/LongitudeOne/Core/Exception/ExceptionInterface.php
index 4361d03..0670c11 100644
--- a/lib/LongitudeOne/Core/Exception/ExceptionInterface.php
+++ b/lib/LongitudeOne/Core/Exception/ExceptionInterface.php
@@ -11,15 +11,6 @@
 
 declare(strict_types=1);
 
-/**
- * This file is part of the LongitudeOne GeoParser project.
- *
- * PHP 8.3 | 8.4 | 8.5
- *
- * Copyright LongitudeOne - Alexandre Tranchant - Derek J. Lambert.
- * Copyright 2024-2026.
- */
-
 namespace LongitudeOne\Core\Exception;
 
 /**
diff --git a/lib/LongitudeOne/Core/Exception/RangeException.php b/lib/LongitudeOne/Core/Exception/RangeException.php
index 810044b..f82b1a2 100644
--- a/lib/LongitudeOne/Core/Exception/RangeException.php
+++ b/lib/LongitudeOne/Core/Exception/RangeException.php
@@ -11,15 +11,6 @@
 
 declare(strict_types=1);
 
-/**
- * This file is part of the LongitudeOne GeoParser project.
- *
- * PHP 8.3 | 8.4 | 8.5
- *
- * Copyright LongitudeOne - Alexandre Tranchant - Derek J. Lambert.
- * Copyright 2024-2026.
- */
-
 namespace LongitudeOne\Core\Exception;
 
 use LongitudeOne\Core\Diagnostic\DiagnosticValueFormatter;
diff --git a/tests/LongitudeOne/Core/Tests/Contract/Diagnostic/DiagnosticValueFormatterContractTest.php b/tests/LongitudeOne/Core/Tests/Contract/Diagnostic/DiagnosticValueFormatterContractTest.php
index 6b24014..2392345 100644
--- a/tests/LongitudeOne/Core/Tests/Contract/Diagnostic/DiagnosticValueFormatterContractTest.php
+++ b/tests/LongitudeOne/Core/Tests/Contract/Diagnostic/DiagnosticValueFormatterContractTest.php
@@ -110,10 +110,10 @@ public function testFormattingIsIdempotent(): void
      */
     public function testHostileCombinedInputRespectsEveryProtection(): void
     {
-        $value = str_repeat("POINT(1 2)\n\x1B[2J\u{202E}", self::MAX_EXPECTED_LENGTH);
+        $value = str_repeat("POINT(1 2)\xC3\n\x1B[2J\u{202E}", self::MAX_EXPECTED_LENGTH);
         $result = DiagnosticValueFormatter::format($value);
 
-        self::assertStringContainsString('POINT(1 2)\n\u{001B}[2J\u{202E}', $result);
+        self::assertStringContainsString('POINT(1 2)\xC3\n\u{001B}[2J\u{202E}', $result);
         self::assertStringNotContainsString("\x1B", $result);
         self::assertStringEndsWith('…', $result);
         $this->assertDiagnosticInvariants($result);
diff --git a/tests/LongitudeOne/Core/Tests/Unit/Diagnostic/DiagnosticValueFormatterTest.php b/tests/LongitudeOne/Core/Tests/Unit/Diagnostic/DiagnosticValueFormatterTest.php
index d5c8e91..44d2e7a 100644
--- a/tests/LongitudeOne/Core/Tests/Unit/Diagnostic/DiagnosticValueFormatterTest.php
+++ b/tests/LongitudeOne/Core/Tests/Unit/Diagnostic/DiagnosticValueFormatterTest.php
@@ -90,5 +90,7 @@ public static function oversizedValues(): iterable
         yield 'plain characters' => [str_repeat('a', DiagnosticValueFormatter::MAX_LENGTH + 1)];
 
         yield 'expanding newlines' => [str_repeat("\n", DiagnosticValueFormatter::MAX_LENGTH)];
+
+        yield 'malformed UTF-8 bytes' => [str_repeat("\xFF", DiagnosticValueFormatter::MAX_LENGTH)];
     }
 }