diff --git a/packages/DeadCode/tests/Rector/Stmt/RemoveDeadStmtRector/RemoveDeadStmtRectorTest.php b/packages/DeadCode/tests/Rector/Stmt/RemoveDeadStmtRector/RemoveDeadStmtRectorTest.php
index 75bdb47fb706..28695673f70e 100644
--- a/packages/DeadCode/tests/Rector/Stmt/RemoveDeadStmtRector/RemoveDeadStmtRectorTest.php
+++ b/packages/DeadCode/tests/Rector/Stmt/RemoveDeadStmtRector/RemoveDeadStmtRectorTest.php
@@ -20,7 +20,7 @@ public function test(string $file): void
 
     public function provideDataForTest(): Iterator
     {
-        yield from $this->yieldFilesFromDirectory(__DIR__ . '/Fixture');
+        return $this->yieldFilesFromDirectory(__DIR__ . '/Fixture');
     }
 
     protected function getRectorClass(): string
diff --git a/packages/Php55/src/Rector/FuncCall/PregReplaceEModifierRector.php b/packages/Php55/src/Rector/FuncCall/PregReplaceEModifierRector.php
index e4a089784c32..155a9ad30e23 100644
--- a/packages/Php55/src/Rector/FuncCall/PregReplaceEModifierRector.php
+++ b/packages/Php55/src/Rector/FuncCall/PregReplaceEModifierRector.php
@@ -133,7 +133,7 @@ private function createAnonymousFunctionFromString(Expr $expr): ?Closure
                 return $node;
             }
 
-            $match = Strings::match($node->value, '#(\\$|\\\\)(?<number>\d+)#');
+            $match = Strings::match($node->value, '#(\\$|\\\\|\\x0)(?<number>\d+)#');
             if (! $match) {
                 return $node;
             }
diff --git a/packages/Php55/tests/Rector/FuncCall/PregReplaceEModifierRector/Fixture/slashes.php.inc b/packages/Php55/tests/Rector/FuncCall/PregReplaceEModifierRector/Fixture/slashes.php.inc
new file mode 100644
index 000000000000..0af60ed7de3d
--- /dev/null
+++ b/packages/Php55/tests/Rector/FuncCall/PregReplaceEModifierRector/Fixture/slashes.php.inc
@@ -0,0 +1,29 @@
+<?php
+
+namespace Rector\Php55\Tests\Rector\FuncCall\PregReplaceEModifierRector\Fixture;
+
+class Slashes
+{
+    public static function camelize($word)
+    {
+        return preg_replace('#a#e', "strtoupper('\\0___');", $word);
+    }
+}
+
+?>
+-----
+<?php
+
+namespace Rector\Php55\Tests\Rector\FuncCall\PregReplaceEModifierRector\Fixture;
+
+class Slashes
+{
+    public static function camelize($word)
+    {
+        return preg_replace_callback('#a#', function ($matches) {
+            return strtoupper($matches[0]);
+        }, $word);
+    }
+}
+
+?>
diff --git a/src/Testing/StaticFixtureProvider.php b/src/Testing/StaticFixtureProvider.php
index 15937953765b..8c159d145bff 100644
--- a/src/Testing/StaticFixtureProvider.php
+++ b/src/Testing/StaticFixtureProvider.php
@@ -10,7 +10,7 @@
 
 final class StaticFixtureProvider
 {
-    public static function yieldFilesFromDirectory(string $directory, string $suffix = '*.php'): Iterator
+    public static function yieldFilesFromDirectory(string $directory, string $suffix): Iterator
     {
         $fileInfos = self::findFilesInDirectory($directory, $suffix);
 
diff --git a/utils/RectorGenerator/templates/packages/_Package_/tests/Rector/_Category_/_Name_/_Name_Test.php.inc b/utils/RectorGenerator/templates/packages/_Package_/tests/Rector/_Category_/_Name_/_Name_Test.php.inc
index ee97cf8350cd..530e939407d2 100644
--- a/utils/RectorGenerator/templates/packages/_Package_/tests/Rector/_Category_/_Name_/_Name_Test.php.inc
+++ b/utils/RectorGenerator/templates/packages/_Package_/tests/Rector/_Category_/_Name_/_Name_Test.php.inc
@@ -18,7 +18,7 @@ final class _Name_Test extends AbstractRectorTestCase
 
     public function provideDataForTest(): \Iterator
     {
-        yield [__DIR__ . '/Fixture/fixture.php.inc'];
+        return $this->yieldFilesFromDirectory(__DIR__ . '/Fixture');
     }
 
     protected function getRectorClass(): string