diff --git a/Library/Optimizers/FunctionCall/IsPhpVersionOptimizer.php b/Library/Optimizers/FunctionCall/IsPhpVersionOptimizer.php
new file mode 100644
index 0000000000..e05ed4a022
--- /dev/null
+++ b/Library/Optimizers/FunctionCall/IsPhpVersionOptimizer.php
@@ -0,0 +1,67 @@
+<?php
+
+/*
+ +--------------------------------------------------------------------------+
+ | Zephir Language                                                          |
+ +--------------------------------------------------------------------------+
+ | Copyright (c) 2013-2014 Zephir Team and contributors                     |
+ +--------------------------------------------------------------------------+
+ | This source file is subject the MIT license, that is bundled with        |
+ | this package in the file LICENSE, and is available through the           |
+ | world-wide-web at the following url:                                     |
+ | http://zephir-lang.com/license.html                                      |
+ |                                                                          |
+ | If you did not receive a copy of the MIT license and are unable          |
+ | to obtain it through the world-wide-web, please send a note to           |
+ | license@zephir-lang.com so we can mail you a copy immediately.           |
+ +--------------------------------------------------------------------------+
+*/
+
+namespace Zephir\Optimizers\FunctionCall;
+
+use Zephir\Call;
+use Zephir\CompilationContext;
+use Zephir\CompilerException;
+use Zephir\CompiledExpression;
+use Zephir\Optimizers\OptimizerAbstract;
+
+/**
+ * IsPhpVersionOptimizer
+ *
+ * Checks if PHP has a specific version
+ */
+class IsPhpVersionOptimizer extends OptimizerAbstract
+{
+    /**
+     *
+     * @param array $expression
+     * @param Call $call
+     * @param CompilationContext $context
+     */
+    public function optimize(array $expression, Call $call, CompilationContext $context)
+    {
+        if (!isset($expression['parameters'])) {
+            throw new CompilerException("This function requires parameters", $expression);
+        }
+
+        if (count($expression['parameters']) != 1) {
+            throw new CompilerException("This function only requires one parameter", $expression);
+        }
+
+        if ($expression['parameters'][0]['parameter']['type'] != 'string') {
+            throw new CompilerException("This function requires a string parameter", $expression);
+        }
+
+        preg_match('/^([0-9]+)\.([0-9]+)\.?([0-9]+)?$/', $expression['parameters'][0]['parameter']['value'], $matches);
+        if (!count($matches)) {
+            throw new CompilerException("Could not parse PHP version", $expression);
+        }
+
+        $major = $matches[1] * 10000;
+        $minor = $matches[2] * 100;
+
+        $version = $major + $minor;
+
+        return new CompiledExpression('bool', 'zephir_is_php_version(' . $version . ')', $expression);
+    }
+}
diff --git a/ext/kernel/fcall.h b/ext/kernel/fcall.h
index 5db822e9c3..d0c9c36d4a 100644
--- a/ext/kernel/fcall.h
+++ b/ext/kernel/fcall.h
@@ -683,7 +683,7 @@ int zephir_call_function(zend_fcall_info *fci, zend_fcall_info_cache *fci_cache
 		} \
 	}
 
-#if PHP_VERSION_ID < 50600
+#ifdef ZEPHIR_RELEASE
 #define ZEPHIR_TEMP_PARAM_COPY 0
 #define zephir_check_temp_parameter(param) do { if (Z_REFCOUNT_P(param) > 1) zval_copy_ctor(param); else ZVAL_NULL(param); } while(0)
 #else
diff --git a/ext/kernel/main.h b/ext/kernel/main.h
index 936483008f..40e3c6ad3d 100644
--- a/ext/kernel/main.h
+++ b/ext/kernel/main.h
@@ -539,4 +539,6 @@ static inline char *_str_erealloc(char *str, size_t new_len, size_t old_len) {
 
 #define ZEPHIR_CHECK_POINTER(v) if (!v) fprintf(stderr, "%s:%d\n", __PRETTY_FUNCTION__, __LINE__);
 
+#define zephir_is_php_version(id) ((PHP_VERSION_ID >= id && PHP_VERSION_ID <= (id + 10000)) ?  1 : 0)
+
 #endif /* ZEPHIR_KERNEL_MAIN_H */
diff --git a/ext/kernel/object.c b/ext/kernel/object.c
index 4f7d797b2f..a49a70b72f 100644
--- a/ext/kernel/object.c
+++ b/ext/kernel/object.c
@@ -1919,6 +1919,7 @@ int zephir_create_instance(zval *return_value, const zval *class_name TSRMLS_DC)
 
 	ce = zend_fetch_class(Z_STRVAL_P(class_name), Z_STRLEN_P(class_name), ZEND_FETCH_CLASS_DEFAULT TSRMLS_CC);
 	if (!ce) {
+		ZVAL_NULL(return_value);
 		return FAILURE;
 	}
 
@@ -1950,6 +1951,7 @@ int zephir_create_instance_params(zval *return_value, const zval *class_name, zv
 
 	ce = zend_fetch_class(Z_STRVAL_P(class_name), Z_STRLEN_P(class_name), ZEND_FETCH_CLASS_DEFAULT TSRMLS_CC);
 	if (!ce) {
+		ZVAL_NULL(return_value);
 		return FAILURE;
 	}
 
@@ -1969,21 +1971,19 @@ int zephir_create_instance_params(zval *return_value, const zval *class_name, zv
 
 			if (likely(param_count) <= 10) {
 				params_ptr = static_params;
-			}
-			else {
+			} else {
 				params_arr = emalloc(param_count * sizeof(zval*));
 				params_ptr = &params;
 			}
 
 			for (
 				zend_hash_internal_pointer_reset_ex(Z_ARRVAL_P(params), &pos);
-				zend_hash_get_current_data_ex(Z_ARRVAL_P(params), (void**)&item, &pos) == SUCCESS;
+				zend_hash_get_current_data_ex(Z_ARRVAL_P(params), (void**) &item, &pos) == SUCCESS;
 				zend_hash_move_forward_ex(Z_ARRVAL_P(params), &pos), ++i
 			) {
 				params_ptr[i] = *item;
 			}
-		}
-		else {
+		} else {
 			params_ptr = NULL;
 		}
 
diff --git a/unit-tests/Extension/BuiltIn/CharMethodTest.php b/unit-tests/Extension/BuiltIn/CharMethodTest.php
index 3e5dd60436..6353f29dbb 100644
--- a/unit-tests/Extension/BuiltIn/CharMethodTest.php
+++ b/unit-tests/Extension/BuiltIn/CharMethodTest.php
@@ -27,7 +27,7 @@ public function testModifications()
     {
         $t = new CharMethods();
 
-        //$this->assertEquals('61', $t->getHex());
-        //$this->assertEquals('68656C6C6F', $t->getHexForString('hello'));
+        $this->assertEquals('61', $t->getHex());
+        $this->assertEquals('68656C6C6F', $t->getHexForString('hello'));
     }
 }