diff --git a/src/TemplateFinder.php b/src/TemplateFinder.php
index 273e69d..f8ed35a 100644
--- a/src/TemplateFinder.php
+++ b/src/TemplateFinder.php
@@ -4,11 +4,14 @@
 
 namespace Madapaja\TwigModule;
 
+use LogicException;
+
 use function assert;
 use function is_int;
 use function str_replace;
 use function strpos;
 use function substr;
+use function var_dump;
 
 class TemplateFinder implements TemplateFinderInterface
 {
@@ -18,6 +21,14 @@ class TemplateFinder implements TemplateFinderInterface
     public function __invoke(string $name): string
     {
         $pos = strpos($name, '/Resource/');
+        if (! is_int($pos)) {
+            var_dump($pos);
+            var_dump($name);
+            if (! is_int($pos)) {
+                throw new LogicException('Resource not found in ' . $name);
+            }
+        }
+
         assert(is_int($pos));
         $relativePath = substr($name, $pos + 10);
 
diff --git a/tests/ExtensionTest.php b/tests/ExtensionTest.php
index 353568c..773b3fc 100644
--- a/tests/ExtensionTest.php
+++ b/tests/ExtensionTest.php
@@ -8,16 +8,20 @@
 use PHPUnit\Framework\TestCase;
 use Ray\Di\Injector;
 
+use function str_replace;
 use function str_rot13;
 use function trim;
 
+use const DIRECTORY_SEPARATOR;
+
 class ExtensionTest extends TestCase
 {
     private Injector $injector;
 
     public function setUp(): void
     {
-        $this->injector = new Injector(new TwigExtensionTestModule([__DIR__ . '/Fake/src/Resource/']));
+        $path = str_replace('/', DIRECTORY_SEPARATOR, __DIR__ . '/Fake/src/Resource/');
+        $this->injector = new Injector(new TwigExtensionTestModule([$path]));
     }
 
     public function testTwigFilter(): void
diff --git a/tests/FileLoaderTest.php b/tests/FileLoaderTest.php
index 61664dd..2e5195f 100644
--- a/tests/FileLoaderTest.php
+++ b/tests/FileLoaderTest.php
@@ -16,13 +16,18 @@
 use ReflectionClass;
 
 use function assert;
+use function str_replace;
 use function trim;
 
+use const DIRECTORY_SEPARATOR;
+
 class FileLoaderTest extends TestCase
 {
     public function getInjector(): Injector
     {
-        return new Injector(new TwigFileLoaderTestModule([__DIR__ . '/Fake/src/Resource']));
+        $path = str_replace('/', DIRECTORY_SEPARATOR, __DIR__ . '/Fake/src/Resource/');
+
+        return new Injector(new TwigFileLoaderTestModule([$path]));
     }
 
     public function testRenderer(): void
@@ -38,11 +43,12 @@ public function testRenderer(): void
     public function testTwigOptions(): void
     {
         /** @var TwigRenderer $renderer */
-        $renderer = (new Injector(new TwigFileLoaderTestModule([__DIR__ . '/Fake/src/Resource'], ['debug' => true])))->getInstance(TwigRenderer::class);
+        $path = str_replace('/', DIRECTORY_SEPARATOR, __DIR__ . '/Fake/src/Resource/');
+        $renderer = (new Injector(new TwigFileLoaderTestModule([$path], ['debug' => true])))->getInstance(TwigRenderer::class);
         $this->assertTrue($renderer->twig->isDebug());
 
         /** @var TwigRenderer $renderer */
-        $renderer = (new Injector(new TwigFileLoaderTestModule([__DIR__ . '/Fake/src/Resource'], ['debug' => false])))->getInstance(TwigRenderer::class);
+        $renderer = (new Injector(new TwigFileLoaderTestModule([$path], ['debug' => false])))->getInstance(TwigRenderer::class);
         $this->assertFalse($renderer->twig->isDebug());
     }
 
@@ -155,7 +161,8 @@ public function testRedirectOnPost(): void
 
     public function testRedirectOnPostNoRedirectTemplate(): void
     {
-        $injector = new Injector(new TwigFileLoaderTestModule([__DIR__ . '/Fake/src/ResourceNoTemplate']));
+        $path = str_replace('/', DIRECTORY_SEPARATOR, __DIR__ . '/Fake/src/ResourceNoTemplate/');
+        $injector = new Injector(new TwigFileLoaderTestModule([$path]));
         $ro = $injector->getInstance(RedirectNoTemplate::class);
         $ro->onPost();
         $view = (string) $ro;
diff --git a/tests/WeavedResourceTest.php b/tests/WeavedResourceTest.php
index 64b5a6f..485953f 100644
--- a/tests/WeavedResourceTest.php
+++ b/tests/WeavedResourceTest.php
@@ -9,15 +9,19 @@
 use Ray\Di\Injector;
 use ReflectionClass;
 
+use function str_replace;
 use function trim;
 
+use const DIRECTORY_SEPARATOR;
+
 class WeavedResourceTest extends TestCase
 {
     private Injector $injector;
 
     public function setUp(): void
     {
-        $this->injector = new Injector(new TwigWeavedResourceTestModule([__DIR__ . '/Fake/src/Resource']));
+        $path = str_replace('/', DIRECTORY_SEPARATOR, __DIR__ . '/Fake/src/Resource/');
+        $this->injector = new Injector(new TwigWeavedResourceTestModule([$path]));
     }
 
     public function testRenderer(): void