diff --git a/CHANGELOG.md b/CHANGELOG.md
index 06b5ebd3..39164d18 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -20,6 +20,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Lexers and Parsers PHP files are no longer under version control, but generated from sources (.y and .plex) 
 - Smarty now always runs in multibyte mode, using `symfony/polyfill-mbstring` if required. Please use the
   multibyte extension for optimal performance.
+- Smarty no longer calls `mb_internal_encoding()` and doesn't check for deprecated `mbstring.func_overload` ini directive [#480](https://github.com/smarty-php/smarty/issues/480)
 
 ### Deprecated
 - `$smarty->getPluginsDir()`
diff --git a/src/Compiler/Configfile.php b/src/Compiler/Configfile.php
index 1eaedb9f..1d50e3f2 100644
--- a/src/Compiler/Configfile.php
+++ b/src/Compiler/Configfile.php
@@ -106,15 +106,6 @@ class Configfile extends BaseCompiler {
 		);
 		/* @var ConfigfileParser $this->parser */
 		$this->parser = new ConfigfileParser($this->lex, $this);
-		if (function_exists('mb_internal_encoding')
-			&& function_exists('ini_get')
-			&& ((int)ini_get('mbstring.func_overload')) & 2
-		) {
-			$mbEncoding = mb_internal_encoding();
-			mb_internal_encoding('ASCII');
-		} else {
-			$mbEncoding = null;
-		}
 		if ($this->smarty->_parserdebug) {
 			$this->parser->PrintTrace();
 		}
@@ -127,9 +118,6 @@ class Configfile extends BaseCompiler {
 		}
 		// finish parsing process
 		$this->parser->doParse(0, 0);
-		if ($mbEncoding) {
-			mb_internal_encoding($mbEncoding);
-		}
 		if ($this->smarty->debugging) {
 			$this->smarty->getDebug()->end_compile($this->template);
 		}
diff --git a/src/Compiler/Template.php b/src/Compiler/Template.php
index 74154020..dc60472f 100644
--- a/src/Compiler/Template.php
+++ b/src/Compiler/Template.php
@@ -1254,15 +1254,6 @@ class Template extends BaseCompiler {
 		if ($isTemplateSource && $this->template->caching) {
 			$this->parser->insertPhpCode("<?php\n\$_smarty_tpl->getCompiled()->nocache_hash = '{$this->nocache_hash}';\n?>\n");
 		}
-		if (function_exists('mb_internal_encoding')
-			&& function_exists('ini_get')
-			&& ((int)ini_get('mbstring.func_overload')) & 2
-		) {
-			$mbEncoding = mb_internal_encoding();
-			mb_internal_encoding('ASCII');
-		} else {
-			$mbEncoding = null;
-		}
 		if ($this->smarty->_parserdebug) {
 			$this->parser->PrintTrace();
 			$this->parser->lex->PrintTrace();
@@ -1277,9 +1268,6 @@ class Template extends BaseCompiler {
 		}
 		// finish parsing process
 		$this->parser->doParse(0, 0);
-		if ($mbEncoding) {
-			mb_internal_encoding($mbEncoding);
-		}
 		// check for unclosed tags
 		if ($this->getTagStackCount() > 0) {
 			// get stacked info
diff --git a/src/Extension/DefaultExtension.php b/src/Extension/DefaultExtension.php
index 569b4e86..2575c903 100644
--- a/src/Extension/DefaultExtension.php
+++ b/src/Extension/DefaultExtension.php
@@ -488,7 +488,7 @@ class DefaultExtension extends Base {
 	 * @link   http://www.ibm.com/developerworks/library/os-php-unicode/index.html#listing3 for inspiration
 	 *
 	 * @param string $string   characters to calculate unicode of
-	 * @param string $encoding encoding of $string, if null mb_internal_encoding() is used
+	 * @param string $encoding encoding of $string
 	 *
 	 * @return array sequence of unicodes
 	 * @author Rodney Rehm
diff --git a/src/Smarty.php b/src/Smarty.php
index 48fb0d47..bdf67ac0 100644
--- a/src/Smarty.php
+++ b/src/Smarty.php
@@ -531,9 +531,6 @@ class Smarty extends \Smarty\TemplateBase
     public function __construct()
     {
 
-        if (is_callable('mb_internal_encoding')) {
-            mb_internal_encoding(\Smarty\Smarty::$_CHARSET);
-        }
         $this->start_time = microtime(true);
         // Check if we're running on Windows
         \Smarty\Smarty::$_IS_WINDOWS = strtoupper(substr(PHP_OS, 0, 3)) === 'WIN';