diff --git a/src/Factories/TestCaseFactory.php b/src/Factories/TestCaseFactory.php
index 0d2a0978..a64cc546 100644
--- a/src/Factories/TestCaseFactory.php
+++ b/src/Factories/TestCaseFactory.php
@@ -110,8 +110,8 @@ public function evaluate(string $filename, array $methods): void
         $relativePath = (string) preg_replace('|%[a-fA-F0-9][a-fA-F0-9]|', '', $relativePath);
         // Remove escaped quote sequences (maintain namespace)
         $relativePath = str_replace(array_map(fn (string $quote): string => sprintf('\\%s', $quote), ['\'', '"']), '', $relativePath);
-        // Limit to A-Z, a-z, 0-9, '_', '-'.
-        $relativePath = (string) preg_replace('/[^A-Za-z0-9\\\\]/', '', $relativePath);
+        // Limit to Unicode letters and numbers.
+        $relativePath = (string) preg_replace('/[^\p{L}\p{N}\\\\]/u', '', $relativePath);
 
         $classFQN = 'P\\'.$relativePath;
 
diff --git a/tests/.snapshots/success.txt b/tests/.snapshots/success.txt
index 7b3d6f9b..2c1d7e38 100644
--- a/tests/.snapshots/success.txt
+++ b/tests/.snapshots/success.txt
@@ -1775,6 +1775,10 @@
   - todo
   - todo in parallel
 
+   PASS  Tests\Visual\UnicodeFilename
+  ✓ filter works with unicode characters in filename
+  ✓ filter with unicode regex matches unicode filename
+
    WARN  Tests\Visual\Version
   - visual snapshot of help command output
 
@@ -1782,4 +1786,4 @@
   ✓ pass with dataset with ('my-datas-set-value')
   ✓ within describe → pass with dataset with ('my-datas-set-value')
 
-  Tests:    2 deprecated, 4 warnings, 5 incomplete, 2 notices, 39 todos, 35 skipped, 1188 passed (2813 assertions)
\ No newline at end of file
+  Tests:    2 deprecated, 4 warnings, 5 incomplete, 2 notices, 39 todos, 35 skipped, 1190 passed (2818 assertions)
\ No newline at end of file
diff --git "a/tests/.tests/Stra\303\237enTest.php" "b/tests/.tests/Stra\303\237enTest.php"
new file mode 100644
index 00000000..682d1062
--- /dev/null
+++ "b/tests/.tests/Stra\303\237enTest.php"
@@ -0,0 +1,3 @@
+<?php
+
+it('tests unicode filename with ß')->assertTrue(true);
diff --git a/tests/Visual/UnicodeFilename.php b/tests/Visual/UnicodeFilename.php
new file mode 100644
index 00000000..d12ed20f
--- /dev/null
+++ b/tests/Visual/UnicodeFilename.php
@@ -0,0 +1,37 @@
+<?php
+
+use Symfony\Component\Process\Process;
+
+test('filter works with unicode characters in filename', function () {
+    $process = new Process([
+        'php',
+        'bin/pest',
+        'tests/.tests/StraßenTest.php',
+        '--colors=never',
+    ], dirname(__DIR__, 2), ['COLLISION_PRINTER' => 'DefaultPrinter', 'COLLISION_IGNORE_DURATION' => 'true']);
+
+    $process->run();
+
+    $output = $process->getOutput();
+
+    expect($output)->toContain('StraßenTest');
+    expect($output)->toContain('tests unicode filename');
+    expect($output)->toContain('1 passed');
+})->skipOnWindows();
+
+test('filter with unicode regex matches unicode filename', function () {
+    $process = new Process([
+        'php',
+        'bin/pest',
+        '--filter=.*Straß.*',
+        'tests/.tests/',
+        '--colors=never',
+    ], dirname(__DIR__, 2), ['COLLISION_PRINTER' => 'DefaultPrinter', 'COLLISION_IGNORE_DURATION' => 'true']);
+
+    $process->run();
+
+    $output = $process->getOutput();
+
+    expect($output)->toContain('StraßenTest');
+    expect($output)->toContain('1 passed');
+})->skipOnWindows();