diff --git a/phpunit/code/re-assign-this.php b/phpunit/code/re-assign-this.php
new file mode 100644
index 00000000..bec6a611
--- /dev/null
+++ b/phpunit/code/re-assign-this.php
@@ -0,0 +1,15 @@
+<?php
+class Foo {
+    function Bar() {
+        $__this = $this;
+        $this = null;
+        debug_backtrace();
+        $this = $__this;
+    }
+}
+
+function main() {
+    $f = new Foo;
+    $f->Bar();
+    echo "OK\n";
+}
\ No newline at end of file
diff --git a/phpunit/src/ClassTest.php b/phpunit/src/ClassTest.php
new file mode 100644
index 00000000..de641eee
--- /dev/null
+++ b/phpunit/src/ClassTest.php
@@ -0,0 +1,10 @@
+<?php
+
+class ClassTest extends \BaseTest
+{
+    public function testReAssignThis()
+    {
+        $this->exec('Cannot re-assign $this', 're-assign-this.php');
+    }
+
+}
diff --git a/phpunit/src/FunctionTest.php b/phpunit/src/FunctionTest.php
index c03ef514..b4bc779e 100644
--- a/phpunit/src/FunctionTest.php
+++ b/phpunit/src/FunctionTest.php
@@ -6,4 +6,5 @@ class FunctionTest extends \BaseTest
     {
         $this->exec('The return type of the function `test` cannot be a reference type', 'function-return-ref.php');
     }
+
 }
diff --git a/src/Php/CompilerBase.php b/src/Php/CompilerBase.php
index 859e36a0..760809cd 100644
--- a/src/Php/CompilerBase.php
+++ b/src/Php/CompilerBase.php
@@ -245,7 +245,7 @@ class CompilerBase extends \PhpAot\Core\Translator
     protected string $buildDir;
     protected int $debugLine = 0;
     protected CLImate $climate;
-    protected bool $defaultNativeType = false;
+    protected bool $defaultNativeType = true;
     protected bool $stubFile = false;
     protected bool $enableProfiler = false;
     protected bool $forTest = false;
diff --git a/src/Php/FuncCallOptimizer.php b/src/Php/FuncCallOptimizer.php
index 926dd2d5..8490e90e 100644
--- a/src/Php/FuncCallOptimizer.php
+++ b/src/Php/FuncCallOptimizer.php
@@ -85,6 +85,9 @@ trait FuncCallOptimizer
         if ($name === 'pow') {
             return 'php::math::pow(' . $getArg(0) . ', ' . $getArg(1) . ')';
         }
+        if ($name === 'strlen') {
+            return 'php::fn::strlen(' . $getArg(0) . ')';
+        }
         if ($name === 'ord') {
             return 'php::fn::ord(' . $getArg(0) . ')';
         }
diff --git a/tests/core/lang/bug21094.phpt b/tests/core/lang/bug21094.phpt
new file mode 100644
index 00000000..dd901012
--- /dev/null
+++ b/tests/core/lang/bug21094.phpt
@@ -0,0 +1,17 @@
+--TEST--
+Bug #21094 (set_error_handler not accepting methods)
+--FILE--
+<?php
+class test {
+    function hdlr($errno, $errstr, $errfile, $errline) {
+        printf("[%d] errstr: %s, errfile: %s, errline: %d\n", $errno, $errstr, $errfile, $errline, $errstr);
+    }
+}
+
+function main() {
+    set_error_handler(array(new test(), "hdlr"));
+    trigger_error("test");
+}
+?>
+--EXPECTF--
+[1024] errstr: test, errfile: %s, errline: %d
diff --git a/tests/core/lang/bug21961.phpt b/tests/core/lang/bug21961.phpt
new file mode 100644
index 00000000..48bd00b1
--- /dev/null
+++ b/tests/core/lang/bug21961.phpt
@@ -0,0 +1,58 @@
+--TEST--
+Bug #21961 (get_parent_class() segfault)
+--FILE--
+<?php
+
+class man
+{
+    public $name, $bars;
+    function __construct()
+    {
+        $this->name = 'Mr. X';
+        $this->bars = array();
+    }
+
+    function getdrunk($where)
+    {
+        $this->bars[] = new bar($where);
+    }
+
+    function getName()
+    {
+        return $this->name;
+    }
+}
+
+class bar extends man
+{
+    public $name;
+
+    function __construct($w)
+    {
+        $this->name = $w;
+    }
+
+    function getName()
+    {
+        return $this->name;
+    }
+
+    function whosdrunk()
+    {
+        $who = get_parent_class($this);
+        if($who == NULL)
+        {
+            return 'nobody';
+        }
+        return eval("return ".$who.'::getName();');
+    }
+}
+
+function main() {
+    $x = new man;
+    $x->getdrunk('The old Tavern');
+    var_dump($x->bars[0]->whosdrunk());
+}
+?>
+--EXPECT--
+string(14) "The old Tavern"
diff --git a/tests/core/lang/bug23624.phpt b/tests/core/lang/bug23624.phpt
new file mode 100644
index 00000000..f8778fff
--- /dev/null
+++ b/tests/core/lang/bug23624.phpt
@@ -0,0 +1,12 @@
+--TEST--
+Bug #23624 (foreach leaves current array key as null)
+--FILE--
+<?php
+    $arr = array ('one', 'two', 'three');
+    var_dump(current($arr));
+    foreach($arr as $key => $value);
+    var_dump(current($arr));
+?>
+--EXPECT--
+string(3) "one"
+string(3) "one"
diff --git a/tests/core/lang/bug26869.phpt b/tests/core/lang/bug26869.phpt
new file mode 100644
index 00000000..065cf1dd
--- /dev/null
+++ b/tests/core/lang/bug26869.phpt
@@ -0,0 +1,15 @@
+--TEST--
+Bug #26869 (constant as the key of static array)
+--FILE--
+<?php
+    define("A", "1");
+    static $a=array(A => 1);
+    var_dump($a);
+    var_dump(isset($a[A]));
+?>
+--EXPECT--
+array(1) {
+  [1]=>
+  int(1)
+}
+bool(true)
diff --git a/tests/core/lang/bug30726.phpt b/tests/core/lang/bug30726.phpt
new file mode 100644
index 00000000..79aeff7d
--- /dev/null
+++ b/tests/core/lang/bug30726.phpt
@@ -0,0 +1,8 @@
+--TEST--
+Bug #30726 (-.1 like numbers are not being handled correctly)
+--FILE--
+<?php
+echo (int) is_float('-.1' * 2), "\n";
+?>
+--EXPECT--
+1